Assessment of Aged Offshore Jacket Type Platforms Considering Environmental Loads and Degradation Parameters

Offshore steel structures are a common investment in oil and gas industries operating in shallow to medium depth seas.These structures have become increasingly popular since the mid-19th century,with a typical design life of 30-50 years.Despite their popularity,the structural integrity of existing offshore structures remains a controversial topic.Environmental loads and material degradation have been identified as significant factors that can compromise the structural integrity of offshore structures.To address this issue,this study aims to investigate the reserved strength capacity of a selected offshore structure located in the Malaysian Seas.The study will explore the effect of oceanographic data,variations in vertical load,and corrosion on the structure’s main members.To determine the impact of each variable on the reserved strength ratio(RSR)of the structure,several pushover analyses were conducted with different variables.Previous literature has shown little or no relationship between seawater wave height,gravity loads,and corrosion allowance on submerged steel members and the RSR of offshore structures.However,this study aims tofill this gap in knowledge by examining these variables’effects on the RSR of offshore structures.The study’sfindings indicate that even a slight increase in wave height can significantly impact the structure’s RSR due to the increase in lateral loading,potentially leading to severe damage to structural components and the foundation model.Additionally,gravity loads had an adverse effect on the RSR of the structure when more than double the vertical load was added.Corrosion allowance was also found to impact the RSR,particularly when assuming significant wall thickness corrosion in primary members.Overall,thefindings of this study have important implications for the design and maintenance of offshore structures.The results suggest that engineers and operators should pay close attention to the potential impacts of environmental loads,such as wave height and gravity loads,and material degradation,such as corrosion allowance,on the structural integrity of offshore structures.This information can be used to optimize the design and maintenance of offshore structures,leading to safer and more efficient operations.

A Global Reliability Assessment Method on Aging Offshore Platforms with Corrosion and Cracks

Corrosion and fatigue cracks are major threats to the structural integrity of aging offshore platforms. For the rational estimation of the safety levels of aging platforms, a global reliability assessment approach for aging offshore platforms with corrosion and fatigue cracks is presented in this paper. The base shear capacity is taken as the global ultimate strength of the offshore platforms. It is modeled as a random process that decreases with time in the presence of corrosion and fatigue crack propagation. And the corrosion and fatigue crack growth rates in the main members and key joints are modeled as random variables. A simulation method of the extreme wave loads which are applied to the structures of offshore platforms is proposed too. Furthermore, the statistics of global base shear capacity and extreme wave loads are obtained by Monte Carlo simulation method. On the basis of the limit state equation of global failure mode, the instantaneous reliability and time dependent reliability assessment methods are both presented in this paper. Finally the instantaneous reliability index and time dependent failure probability of a jacket platform are estimated with different ages in the demonstration example.

Safety assessment of platform loadout procedures based on unascertained measures

Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they cannot make the reliability adequately explicable. Therefore, a mathematical tool, the unascertained measure, was introduced. First, the basic knowledge of the unascertained sets was introduced briefly. Second, the unascertained measure was defined and credible identification was set up. The method has been introduced into the fields for safety assessment of a jacket loadout procedure. Engineering practices showed that it can complete the safety assessment systematically and scientifically without any assumption. The work should have significance in theory and practice for offshore engineering.

Fire Risk Quantitative Assessment of Offshore Supported Platform

The living area of an offshore platform is the main living place for operators in offshore oil and gas fields.Fire risk assessment plays an important role in the safety of personnel in offshore platforms.In this paper,a fire risk assessment mathematical model for offshore platfoms is proposed based on a comprehensive safety assessment method.The concept of danger time is presented according to the evaluation criteria of safe evacuation.The fire risk of offshore platforms is assessed by combining probability statistics with numerical simulation.The fire risk is quantitatively assessed by using an N500 deep water semi-submersible support platform as an example.According to the FN curve,fire frequency,fire escalation probability,and casualty probability,the rationality of marine general layout is analyzed,and the general layout design could be optimized to reduce the fire risk.

Study of The Technical Index of Online Learning Behavior Analysis of Nursing Majors on The Superstar Platform Based on The Kirkpatrick Evaluation Model

Objective:To analyze the technical indexes of students’online learning behavior analysis based on Kirkman’s evaluation model,sort out the basic indexes of online learning behavior,and extract scientific and efficient evaluation indexes of online learning effect through statistical analysis.Methods:The online learning behavior data of Physiology of nursing students from 2021-2023 and the first semester of 22 nursing classes(3 and 4)were collected and analyzed.The preset learning behavior indexes were analyzed by multi-dimensional analysis and a correlation analysis was conducted between the indexes and the final examination scores to screen for the dominant important indexes for online learning effect evaluation.Results:The study found that the demand for online learning of nursing students from 2021-2023 increased and the effect was statistically significant.Compared with the stage assessment results,the online learning effect was statistically significant.Conclusion:The main indicators for evaluating and classifying online learning behaviors were summarized.These two indicators can help teachers predict which part of students need learning intervention,optimize the teaching process,and help students improve their learning behavior and academic performance.

A Study on College English Blending Teaching Assessment System Based on SPOC Platform

Due to the rapid development of modern science and technology, college English teaching has been improved according-ly. With their integration, the teaching method gets constantly updated, and the teaching resources are greatly enriched, which con-spicuously enhances the teaching effect, and is embraced by students. Teaching assessment is a key link in college English teach-ing. Establishing a scientific and perfect assessment system is also an important means to achieve teaching goals, and thus it is im-perative to establish a scientific and reasonable assessment system based on the SPOC platform for college English blended teach-ing. The present paper argues the assessment system from two aspects:establishing assessment criteria and setting up the content of assessment. It aims to establish a scientific and perfect assessment system to promote students'growth, and improve the quality of teaching as well as personnel training.

Cloud Data and Computing Services Allow Regional Environmental Assessment:A Case Study of Macquarie-Castlereagh Basin, Australia

Large amounts of data at various temporal and spatial scales require terabyte(TB) level storage and computation, both of which are not easy for researchers to access. Cloud data and computing services provide another solution to store, process, share and explore environmental data with low costs, stronger computation capacity and easy access. The purpose of this paper is to examine the benefits and challenges of using freely available satellite data products from Australian Geoscience DataCube and Google Earth Engine(GEE) online data with time series for integrative environmental analysis of the Macquarie-Castlereagh Basin in the last 15 years as a case study. Results revealed that the cloud platform simplifies the procedure of traditional catalog data processing and analysis. The integrated analysis based on the cloud computing and traditional methods represents a great potential as a low-cost, efficient and user-friendly method for global and regional environmental study. The user can save considerable time and cost on data integration. The research shows that there is an excellent promise in performing regional environmental analysis by using a cloud platform. The incoming challenge of the cloud platform is that not all kinds of data are available on the cloud platform. How data are integrated into a single platform while protecting or recognizing the data property, or how one portal can be used to explore data archived on different platforms represent considerable challenges.

System Reliability Analysis of Offshore Strctures and Component Safety Rank Assessment

Offshore structures will encounter serious environmental load, so it is important to study the structural system reliability and to evaluate the structural component safety rank. In this paper, the bracnch-and-bound method is adopted to search the main failure path, and the Ditlevsen bound method is used to calculate the system failure probability. The structure is then assessed by the fuzzy comprehensive assessment method, which evaluates the structural component safety rank. The ultimate equation of the tubular cross- section is analyzed on the basis of ultimate stregnth analysis. The influence of effect coefficients on the structural system failure probability is investigated, and basic results are obtained. A general program for spatial frame structures by means of the above method is developed, and verified by the numerical examples.

Teaching Reform for Mobile Application Development with Industrial Projects,Double Instructors,and Automatic Assessments

Mobile Application Development is a well-known undergraduate specialized course majoring in Computer Science and Software Engineering.Since it is a rapid developing technique and requires extensive project samples to help understand,current teaching mechanism has still limitations in rare real project examples,outdated course contents,and lack of automatic assessment platforms.In order to improve the teaching effects and cultivate students’practical ability,we employ this teaching reform with industrial projects,double instructors,and automatic assessment platform to allow students participating in every course process.We aim to improve students’practical and collaboration ability during conducting the project spontaneously,and cultivate their awareness of self-learning and lifelong learning.Our classroom feedback has demonstrated that this teaching reform is effective on improving students’practical abilities,learning initiatives and comprehensive qualities.

基于放电电压平台研究的蓄电池寿命状态评估

为解决传统动车组镍镉蓄电池的返修方法导致部分蓄电池在触发返修条件前已性能劣化,同时大量已达返修标准的蓄电池性能并未过度衰退的问题,设计单体镍镉蓄电池全寿命加速老化实验并获取相关实验数据。首先,采用集成经验模态方法建立单体电池全寿命健康状态类别划分模型,然后运用离散小波变换消除放电电压平台数据的奇异值,进而利用极限学习机算法预测蓄电池寿命状态,最终实现对蓄电池全生命周期寿命的准确预测与健康状态评估功能。实验结果表明:相较于传统的蓄电池寿命阈值分类方法,运用集成经验模态建立的健康状态类别划分模型能有效避免蓄电池寿命末端出现误警情况。作为融合算法模型输入的放电电压平台数据易获取,基于离散小波变换的数据预处理方法可提升算法准确率近3%,最终可达到96%~98%。此外,相对于传统的神经网络模型,融合算法模型不涉及迭代,因而能兼顾算法的预测精度与计算效能。蓄电池识别健康状态的F1值为0.976 3,识别老化阶段的F1值为0.950 9,识别故障阶段的F1值为0.939 394。相较于传统的依据动车组运营里程和使用年限进而决定蓄电池是否返修的方法,融合算法模型提供了显著的评判标准,能判别蓄电池是否应该返修,并有效地识别蓄电池的健康状态,降低了动车组的运营成本,保障动车组运营安全,为电池寿命评判和检修策略的优化提供参考。

基于Sakai平台的过程考核教学模型与应用

过程考核是科学评价一门课程教学质量的关键,已成为教育领域关注的热点。如何将过程考核科学地渗入到一门课程的教学过程中,对于提升课程教学的学习质量和效率尤为重要。基于Sakai平台,提出过程考核“五力”教学模型,该模型包括作业、测验、讨论、期中、拓展五个考核环节。在课程教学应用中,“五力”模型过程考核教学模式,激发学生课余时间主动学习的兴趣,拓展学生的知识面,提升课程知识点的学习质量,同时有效提高教师过程考核的效率。

水下平台潜在区域威胁评估方法

为进一步提升对水下平台任务过程的复盘量化分析能力,分析开展水下平台潜在任务空间区域威胁评估迫切需求,讨论了水下平台潜在活动区域所面临的主要威胁因素和典型海洋环境影响因素;从威胁评估特征分析及指标体系构建、贝叶斯网络构造与推理以及威胁评估仿真实验设计3方面论述了水下平台潜在区域威胁评估方法,给出了水下平台潜在区域威胁评估典型实验过程及结果;对水下平台潜在区域威胁评估方法在水下平台任务复盘评估保障应用前景进行了展望。

某三级甲等医院构建基础医疗质量评价体系的实践探索

构建并完善基础医疗质量评价体系,提升医疗质量与安全。以某三级甲等医院为例,该院从患者服务、手术管理、危急重症、病历质量、合理诊疗、科室管理6个维度构建基础医疗质量评价体系,在体系中增加专项质控考核和平台科室质量评价体系,将评价结果与科主任管理绩效和科室绩效挂钩,并在此基础上构建科主任评价体系。该体系的构建形成了全方位医疗质量监管机制,激发科室主动参与质控管理,有助于发现医疗质量薄弱环节并持续改进,并可实现医疗质量安全的分层管理。基础医疗质量评价体系的建立有助于全方位了解全院科室医疗质量管理问题,提升质控管理成效,为医院夯实高质量发展根基。

依托超星平台实现“电子技术实验”考核

分析目前“电子技术实验”课程考核中存在的问题,以“模拟电子技术实验”为例,依托超星平台,建立了多维度的过程性考核体系。利用超星平台的统计和评价功能,将学生的成绩分为线上和线下两部分,线上成绩包括预习和测验。线下成绩包括实验操作,实验报告和素养成绩。实践证明,多维度的过程性考核体系能大大提高学生的学习兴趣,提升学生的综合能力和创新能力,能全面客观地评价学生的学习效果和极大地提升实验教学质量。

基于集对分析理论和数字化平台的山岭隧道塌方风险评价

为更准确、更科学地完成山岭隧道塌方风险评价,提出一种基于层次分析法(AHP)-熵值法(Entropy)集对分析理论的山岭隧道塌方风险评价方法。首先,选取地质因素、设计因素、施工因素、管理因素4项因素作为塌方风险评价指标体系的准则层,选取12项因素作为指标层,运用层次分析法和熵值法分别计算2级指标权重;然后,引入集对分析理论确定指标联系度,并结合置信度准则对塌方风险的等级进行判定;接着,利用Grasshopper以及Python软件,对集对分析理论进行可视化程序开发,并将其与隧道-地质BIM交互模型进行耦合,建立基于AHP-Entropy集对分析模型的隧道塌方风险数字化分析平台;最后,结合重庆某隧道实际工程,验证隧道塌方风险评价的高效化、可视化效果。研究表明:基于集对分析理论的山岭隧道塌方风险评价数字化分析平台运行时间约为2 s,与传统的隧道塌方风险评价方法相比可以大大提高风险评价效率,同时利用AHP-Entropy法确定评价指标权重,提高了评价结果的可靠性。

基于“学习通”平台的《财政学》课程考核改革与实践

在信息技术与教育教学深度融合的政策背景下,选用“学习通”平台对课程数据进行科学的获取、加工、传输、分析和使用,将评价成果与线上线下的教学活动共享互联,有利于教育评价的自动化和智能化,从而达到变革模式和提升质量的目标。本文以《财政学》课程为例,构建基于“学习通”平台的“课前—课中—课后”全过程课程考核体系,以期为建设高效率课程评价做参考。

信息化时代“图像处理技术”课程建设与实践

文章针对信息化背景下学习活动模块化、时间碎片化和普通高等教育电子信息类专业课教学的自身特性,利用一体化平台整合教学资源,开展线上线下双线教学,同时实现教学全过程动态管理和成绩评价指标的量化记录;根据“图像处理技术”课程实践性强、应用广泛的特点,结合科研工程案例,利用平台开展翻转课堂形式的教学活动,并在教学过程中融入思政元素,激发学生学习积极性,增强学生的法律意识和科技强国的责任感;同时完善课程考核体系,提高课程参与度,取得了一定的实践效果。

潜在区域水下威胁评估仿真实验系统设计实现

为提升作战人员对水下战场态势的理解能力及其水下威胁评估分析水平,综合典型作战仿真实验评估方法特点,从信息输入、数据驱动及评估计算三方面分析了水下平台潜在区域威胁评估仿真实验需求和威胁评估实验方法选择依据,给出了由作战实验仿真控制、作战实验数据管理、作战实验数据评估以及海洋环境效应仿真等四部分组成的系统总体架构及分系统功能设计实现思路,并从评估方案生成与推演控制、信号级声学传感器环境效应仿真以及仿真实验可视化评估等方面总结了系统实现的关键仿真技术。通过系统设计工程化实现及迭代升级,对于探索水下平台任务评估保障机制、提高训练效益具有支撑作用。

以学生为中心的“工程测量学”教学改革探索

秉承“以学生为中心、持续改进”的教育教学理念,以能力培养为导向,对“工程测量学”课程内容和教学模式进行优化设计,搭建在线学习平台,为学生提供全方位的学习指导,以便学生随时随地完成学习任务;开发测量实验在线预约系统,为课程期间由于不可抗力未能完成测量实验的学生开辟渠道,完成实验内容;采用线上线下有机结合的方式,增强过程性考核的客观性,完善课程教学过程性考核的评价方式,提高教学效率,以此保障教学活动的顺利开展,提高教学质量,达到教学目的。

海上石油平台延寿技术及应用研究

目前海上石油平台的设计寿命一般在15~20年,由于实际生产和节约开采成本的需要,超设计寿命平台仍然具有很高的利用价值,需要对其进行评估、延寿、维修,以保证海上的油气勘探开发效益最大化。本文以浅海固定式石油平台为研究对象,提出延寿评估方法,为平台安全运营、效益生产提供技术支撑。