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Rethinking Chart Understanding Using Multimodal Large Language Models
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作者 Andreea-Maria Tanasa Simona-Vasilica Oprea 《Computers, Materials & Continua》 2025年第8期2905-2933,共29页
Extracting data from visually rich documents and charts using traditional methods that rely on OCR-based parsing poses multiple challenges,including layout complexity in unstructured formats,limitations in recognizing... Extracting data from visually rich documents and charts using traditional methods that rely on OCR-based parsing poses multiple challenges,including layout complexity in unstructured formats,limitations in recognizing visual elements,and the correlation between different parts of the documents,as well as domain-specific semantics.Simply extracting text is not sufficient;advanced reasoning capabilities are proving to be essential to analyze content and answer questions accurately.This paper aims to evaluate the ability of the Large Language Models(LLMs)to correctly answer questions about various types of charts,comparing their performance when using images as input versus directly parsing PDF files.To retrieve the images from the PDF,ColPali,a model leveraging state-of-the-art visual languagemodels,is used to identify the relevant page containing the appropriate chart for each question.Google’s Gemini multimodal models were used to answer a set of questions through two approaches:1)processing images derived from PDF documents and 2)directly utilizing the content of the same PDFs.Our findings underscore the limitations of traditional OCR-based approaches in visual document understanding(VrDU)and demonstrate the advantages of multimodal methods in both data extraction and reasoning tasks.Through structured benchmarking of chart question answering(CQA)across input formats,our work contributes to the advancement of chart understanding(CU)and the broader field of multimodal document analysis.Using two diverse and information-rich sources:the World Health Statistics 2024 report by theWorld Health Organisation and the Global Banking Annual Review 2024 by McKinsey&Company,we examine the performance ofmultimodal LLMs across different input modalities,comparing their effectiveness in processing charts as images versus parsing directly from PDF content.These documents were selected due to their multimodal nature,combining dense textual analysis with varied visual representations,thus presenting realistic challenges for vision-language models.This comparison is aimed at assessing how advanced models perform with different input formats and to determine if an image-based approach enhances chart comprehension in terms of accurate data extraction and reasoning capabilities. 展开更多
关键词 chart understanding large language models multimodal models PDF extraction
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Explicit ARL Computational for a Modified EWMA Control Chart in Autocorrelated Statistical Process Control Models
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作者 Yadpirun Supharakonsakun Yupaporn Areepong Korakoch Silpakob 《Computer Modeling in Engineering & Sciences》 2025年第10期699-720,共22页
This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving ... This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving average behavior—SARMA(1,1)L under exponential white noise.Unlike previous works that rely on simplified models such as AR(1)or assume independence,this research derives for the first time an exact two-sided Average Run Length(ARL)formula for theModified EWMAchart under SARMA(1,1)L conditions,using a mathematically rigorous Fredholm integral approach.The derived formulas are validated against numerical integral equation(NIE)solutions,showing strong agreement and significantly reduced computational burden.Additionally,a performance comparison index(PCI)is introduced to assess the chart’s detection capability.Results demonstrate that the proposed method exhibits superior sensitivity to mean shifts in autocorrelated environments,outperforming existing approaches.The findings offer a new,efficient framework for real-time quality control in complex seasonal processes,with potential applications in environmental monitoring and intelligent manufacturing systems. 展开更多
关键词 Statistical process control average run length modified EWMA control chart autocorrelated data SARMA process computational modeling real-time monitoring
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Trend Autoregressive Model Exact Run Length Evaluation on a Two-Sided Extended EWMA Chart
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作者 Kotchaporn Karoon Yupaporn Areepong Saowanit Sukparungsee 《Computer Systems Science & Engineering》 SCIE EI 2023年第2期1143-1160,共18页
The Extended Exponentially Weighted Moving Average(extended EWMA)control chart is one of the control charts and can be used to quickly detect a small shift.The performance of control charts can be evaluated with the a... The Extended Exponentially Weighted Moving Average(extended EWMA)control chart is one of the control charts and can be used to quickly detect a small shift.The performance of control charts can be evaluated with the average run length(ARL).Due to the deriving explicit formulas for the ARL on a two-sided extended EWMA control chart for trend autoregressive or trend AR(p)model has not been reported previously.The aim of this study is to derive the explicit formulas for the ARL on a two-sided extended EWMA con-trol chart for the trend AR(p)model as well as the trend AR(1)and trend AR(2)models with exponential white noise.The analytical solution accuracy was obtained with the extended EWMA control chart and was compared to the numer-ical integral equation(NIE)method.The results show that the ARL obtained by the explicit formula and the NIE method is hardly different,but the explicit for-mula can help decrease the computational(CPU)time.Furthermore,this is also expanded to comparative performance with the Exponentially Weighted Moving Average(EWMA)control chart.The performance of the extended EWMA control chart is better than the EWMA control chart for all situations,both the trend AR(1)and trend AR(2)models.Finally,the analytical solution of ARL is applied to real-world data in the healthfield,such as COVID-19 data in the United Kingdom and Sweden,to demonstrate the efficacy of the proposed method. 展开更多
关键词 Average run length explicit formula extended EWMA chart trend autoregressive model
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A structural VAR and VECM modeling method for open-high-low-close data contained in candlestick chart
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作者 Wenyang Huang Huiwen Wang Shanshan Wang 《Financial Innovation》 2024年第1期2017-2045,共29页
The structural modeling of open-high-low-close(OHLC)data contained within the candlestick chart is crucial to financial practice.However,the inherent constraints in OHLC data pose immense challenges to its structural ... The structural modeling of open-high-low-close(OHLC)data contained within the candlestick chart is crucial to financial practice.However,the inherent constraints in OHLC data pose immense challenges to its structural modeling.Models that fail to process these constraints may yield results deviating from those of the original OHLC data structure.To address this issue,a novel unconstrained transformation method,along with its explicit inverse transformation,is proposed to properly handle the inherent constraints of OHLC data.A flexible and effective framework for structurally modeling OHLC data is designed,and the detailed procedure for modeling OHLC data through the vector autoregression and vector error correction model are provided as an example of multivariate time-series analysis.Extensive simulations and three authentic financial datasets from the Kweichow Moutai,CSI 100 index,and 50 ETF of the Chinese stock market demonstrate the effectiveness and stability of the proposed modeling approach.The modeling results of support vector regression provide further evidence that the proposed unconstrained transformation not only ensures structural forecasting of OHLC data but also is an effective feature-extraction method that can effectively improve the forecasting accuracy of machine-learning models for close prices. 展开更多
关键词 OHLC data Structural modeling Unconstrained transformation Candlestick chart VAR VECM
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肺腺癌一线化疗患者顺铂化疗抵抗的影响因素及其列线图预测模型的构建
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作者 郭运杰 井小会 +1 位作者 宁飘飘 王瑞琳 《实用癌症杂志》 2026年第1期108-113,共6页
目的探究肺腺癌一线化疗患者顺铂化疗抵抗发生的影响因素,并构建列线图风险预测模型。方法选择104例肺腺癌一线化疗患者作为研究对象,统计患者化疗期间顺铂化疗抵抗发生情况;设计基线资料调查表采集患者的临床资料,采用单因素、多因素Lo... 目的探究肺腺癌一线化疗患者顺铂化疗抵抗发生的影响因素,并构建列线图风险预测模型。方法选择104例肺腺癌一线化疗患者作为研究对象,统计患者化疗期间顺铂化疗抵抗发生情况;设计基线资料调查表采集患者的临床资料,采用单因素、多因素Logistic回归分析肺腺癌患者一线化疗过程中顺铂化疗抵抗发生的影响因素,并构建列线图风险预测模型。绘制受试者工作特征(ROC)曲线验证该模型的预测价值,并绘制决策曲线评估该模型的临床获益情况。结果经4个周期的一线化疗后,顺铂化疗抵抗发生率为41.35%(43/104)。单因素分析结果显示,发生组肿瘤直径大于未发生组,CEA、CA125水平高于未发生组,且营养不良、低分化/未分化、未联合靶向治疗、甲状腺转录因子-1(TTF-1)阴性的患者占比均高于未发生组,差异有统计学意义(P<0.05);多因素Logistic回归分析结果显示:肿瘤直径大、低分化/未分化、营养不良、未联合靶向治疗、TTF-1阴性是肺腺癌一线化疗患者顺铂化疗抵抗发生的独立危险因素(OR>1,P<0.05)。构建列线图风险预测模型,验证模型显示C-index=0.843,具有良好区分度;绘制ROC曲线,结果显示,列线图风险预测模型评估肺腺癌一线化疗患者顺铂化疗抵抗发生的AUC为0.843,AUC的95%置信区间为0.769~0.917,P<0.001,敏感度为0.814,特异度为0.754,约登指数为0.568;绘制决策曲线,结果显示,在阈值0.00~0.87范围内具有更高的净收益率,最大净收益率为0.370,提示该模型具有较好的预测价值。结论肿瘤直径大、低分化/未分化、营养不良、未联合靶向治疗、TTF-1阴性是肺腺癌一线化疗患者顺铂化疗抵抗发生的独立危险因素,基于上述因素构建的列线图风险预测模型可较好预测患者顺铂化疗抵抗发生风险。 展开更多
关键词 肺腺癌 一线化疗 顺铂化疗抵抗 影响因素 列线图 预测模型
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罂粟碱致药品不良反应的影响因素分析与预测模型构建
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作者 丁萍 金亮 +1 位作者 陈震 张旺 《中国药业》 2026年第3期138-141,共4页
目的促进罂粟碱的临床合理用药。方法回顾性收集医院2023年5月至2025年4月使用注射用罂粟碱住院患者的临床资料186份,涉及患者186例。根据是否发生药品不良反应(ADR)将患者分为观察组(45例)和对照组(141例)。采用单因素及多因素Logisti... 目的促进罂粟碱的临床合理用药。方法回顾性收集医院2023年5月至2025年4月使用注射用罂粟碱住院患者的临床资料186份,涉及患者186例。根据是否发生药品不良反应(ADR)将患者分为观察组(45例)和对照组(141例)。采用单因素及多因素Logistic回归分析确定发生ADR的独立危险因素,并据此构建列线图预测模型,结合受试者工作特征(ROC)曲线与校准曲线进行预测模型可靠性的内部与外部验证。结果多因素Logistic回归分析结果显示,年龄≥65岁、单次给药剂量≥30 mg、合并疾病数>5种、滴速≥40滴/分为罂粟碱致ADR的危险因素。基于上述4个变量构建的列线图模型的ROC曲线下与坐标轴围成的面积(AUC)为0.824,外部验证预测的总体准确率为77.78%。结论临床使用罂粟碱时应关注高龄、合并多种疾病、单次给药剂量较大、滴速较快等高风险人群。构建的预测模型的区分度良好,可为临床提供有效的ADR风险预警工具,并可提升罂粟碱的合理使用水平,促进患者安全用药。 展开更多
关键词 罂粟碱 药品不良反应 风险因素 列线图 预测模型 合理用药
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构建个体化预测支气管哮喘儿童规范治疗停药后复发风险的列线图模型
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作者 李湘云 杨坤良 阳丽琼 《临床肺科杂志》 2026年第1期65-70,共6页
目的探讨支气管哮喘(BA)儿童规范治疗停药后复发的危险因素,并构建个体化预测复发的列线图模型。方法选择2020年6月至2022年9月本院收治的BA患儿,均在规范治疗后停药。对患儿开展1年的随访,了解复发情况并分成复发组和对照组。获取两组... 目的探讨支气管哮喘(BA)儿童规范治疗停药后复发的危险因素,并构建个体化预测复发的列线图模型。方法选择2020年6月至2022年9月本院收治的BA患儿,均在规范治疗后停药。对患儿开展1年的随访,了解复发情况并分成复发组和对照组。获取两组患者资料进行比较,利用多因素分析筛查BA患儿停药后复发的相关因素,并构建预测模型。通过ROC和校准曲线对模型的预测效果(区分度及准确性)予以评估。结果共纳入156例患儿,其中停药后复发91例,复发率为58.33%。复发组合并过敏性鼻炎情况、哮喘程度、治疗方案、ICS疗程、停药前稳定时间及停药时FeNO值和对照组有统计学差异(P<0.05)。Logistic回归筛查出合并过敏性鼻炎(OR=4.288,95%CI:1.801~10.208)、重度或危重度哮喘(OR=6.917,95%CI:2.307~20.736)、ICS疗程<12个月(OR=6.926,95%CI:2.213~21.672)、停药前稳定时间<3个月(OR=4.724,95%CI:1.521~14.669)、停药时FeNO高水平(OR=3.128,95%CI:1.445~6.773)5个预测因子,基于上述因子构建预测停药后复发风险的列线图模型,内部验证显示,ROC曲线下面积(AUC)为0.800(95%CI:0.732~0.868),预测BA患儿停药后复发的概率接近实际概率,拟合优度H-L检验χ^(2)=0.894,P=0.440。结论根据合并过敏性鼻炎情况、哮喘程度、ICS疗程、停药前稳定时间、停药时FeNO值构建的列线图模型可对BA患儿停药后复发风险进行有效预测。 展开更多
关键词 支气管哮喘 儿童 规范化治疗 复发 列线图模型
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胆总管结石患者内镜下逆行胰胆管造影术后恶性梗阻性黄疸发生风险的列线图预测模型构建
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作者 李义安 张伟 马朝建 《中国当代医药》 2026年第2期9-13,共5页
目的分析并构建胆总管结石患者经内镜下逆行胰胆管造影术(ERCP)后恶性梗阻性黄疸(MOJ)发生风险的列线图预测模型。方法选取2021年6月至2024年2月吉安市中心人民医院行ERCP手术的285例胆总管结石患者为研究对象,据其术后是否出现MOJ分为... 目的分析并构建胆总管结石患者经内镜下逆行胰胆管造影术(ERCP)后恶性梗阻性黄疸(MOJ)发生风险的列线图预测模型。方法选取2021年6月至2024年2月吉安市中心人民医院行ERCP手术的285例胆总管结石患者为研究对象,据其术后是否出现MOJ分为黄疸组(n=51)和非黄疸组(n=234),比较两组基线资料,采用ROC和logistic回归分析影响ERCP术后患者MOJ发生的相关因素并构建列线图预测模型。结果单因素分析结果显示,患者术后发生MOJ与年龄、体重指数、糖尿病、脂肪肝、胆囊切除史、胆总管直径、结石直径及手术时间有关,差异有统计学意义(P<0.05)。多因素分析结果显示,年龄(β=0.046,OR=1.047,95%CI:1.010~1.085),糖尿病(β=1.095,OR=2.988,95%CI:1.312~6.805),脂肪肝(β=1.135,OR=3.111,95%CI:1.373~7.047),胆总管直径(β=0.180,OR=1.197,95%CI:1.033~1.387),结石直径(β=0.203,OR=1.225,95%CI:1.072~1.401),手术时间(β=0.033,OR=1.034,95%CI:1.017~1.051)是胆总管结石ERCP术后患者MOJ的独立危险因素(P<0.05)。年龄、脂肪肝、胆总管直径、手术时间对患者术后MOJ的发生有预测价值,AUC为0.614、0.595、0.616、0.686(P<0.05);C-index=0.792(0.722~0.861)显示一致性较好;Hosmer-Lemeshow检验显示χ2=7.167,P=0.519,表明逻辑回归模型对数据的拟合效果良好。结论年龄、糖尿病、脂肪肝、胆总管直径、结石直径及手术时间是患者术后发生MOJ的影响因素,且模型有较好的预测能力。 展开更多
关键词 胆总管结石 内镜下逆行胰胆管造影术 恶性梗阻性黄疸 列线图预测模型
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Stochastic Model for Multiple Classes and Subclasses Simple Documents Processing 被引量:1
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作者 Pierre Moukeli Mbindzoukou Arsène Roland Moukoukou Marius Massala 《Intelligent Information Management》 2021年第2期124-140,共17页
The issue of document management has been raised for a long time, especially with the appearance of office automation in the 1980s, which led to dematerialization and Electronic Document Management (EDM). In the same ... The issue of document management has been raised for a long time, especially with the appearance of office automation in the 1980s, which led to dematerialization and Electronic Document Management (EDM). In the same period, workflow management has experienced significant development, but has become more focused on the industry. However, it seems to us that document workflows have not had the same interest for the scientific community. But nowadays, the emergence and supremacy of the Internet in electronic exchanges are leading to a massive dematerialization of documents;which requires a conceptual reconsideration of the organizational framework for the processing of said documents in both public and private administrations. This problem seems open to us and deserves the interest of the scientific community. Indeed, EDM has mainly focused on the storage (referencing) and circulation of documents (traceability). It paid little attention to the overall behavior of the system in processing documents. The purpose of our researches is to model document processing systems. In the previous works, we proposed a general model and its specialization in the case of small documents (any document processed by a single person at a time during its processing life cycle), which represent 70% of documents processed by administrations, according to our study. In this contribution, we extend the model for processing small documents to the case where they are managed in a system comprising document classes organized in subclasses;which is the case for most administrations. We have thus observed that this model is a Markovian <i>M<sup>L×K</sup>/M<sup>L×K</sup>/</i>1 queues network. We have analyzed the constraints of this model and deduced certain characteristics and metrics. <span style="white-space:normal;"><i></i></span><i>In fine<span style="white-space:normal;"></span></i>, the ultimate objective of our work is to design a document workflow management system, integrating a component of global behavior prediction. 展开更多
关键词 Document Processing WORKFLOW Hierarchic chart Counting Processes Stochastic models Waiting Lines Markov Processes Priority Queues Multiple Class and Subclass Queues
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Production Planning and Management Using Gantt Charts 被引量:3
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作者 Masahiro Shibuya Xuebin Chen 《Journal of Mechanics Engineering and Automation》 2021年第3期68-76,共9页
In this paper,a support method for business planning and management using software is proposed in order to increase productivity in small and medium-sized industries.Our targets are job shop type production factories,... In this paper,a support method for business planning and management using software is proposed in order to increase productivity in small and medium-sized industries.Our targets are job shop type production factories,which manufacture products that meet specific demands from numerous customers.For these factories to be successful,speedy operational planning and effective management of operations progress for different models in variable quantities are essential.Moreover,effective production and operations management needs to be promoted.Thus,it is necessary to obtain a tool that enables the maximization of throughput using a bird’s-eye view of the entire shop floor and understanding it from the viewpoint of optimization.In our study,planning production and expediting follow-up are conducted using Gantt charts.The system is a simple analog tool that heuristically supports production management through worksite knowledge and experiences without conventional approaches.Furthermore,robotic process automation(RPA)was introduced to reduce the workload of workers.The effectiveness of this prototype system was confirmed by a review of different people in charge. 展开更多
关键词 Gantt chart MZ platform VISUALIZATION Ho-Ren-So open-source model
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基于Ajax技术的ECharts实时图形报表实现 被引量:10
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作者 王菲露 李军 +2 位作者 宋杨 胡勇 陈玉峰 《黑龙江工业学院学报(综合版)》 2019年第12期79-83,共5页
基于Ajax技术、采用异步交互方法实现了ECharts饼形图与柱形图的实时刷新。该动态数据实时刷新技术充分结合了Ajax技术和ECharts技术的特性,实现了前端页面的实时刷新无等待。同时以ECharts为主体形成的图表呈现效果清晰直观,提高了人... 基于Ajax技术、采用异步交互方法实现了ECharts饼形图与柱形图的实时刷新。该动态数据实时刷新技术充分结合了Ajax技术和ECharts技术的特性,实现了前端页面的实时刷新无等待。同时以ECharts为主体形成的图表呈现效果清晰直观,提高了人机交互水平,拥有很好的用户体验。与传统Web应用相比较结果表明,Ajax技术的异步交互方法在软件开发过程中有更好的应用价值和开发意义。 展开更多
关键词 AJAX Echarts WEB MVC开发模式 请求流程
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Fibonacci Harmonics: A New Mathematical Model of Synchronicity
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作者 Robert G. Sacco 《Applied Mathematics》 2018年第6期702-718,共17页
This article aims to provide a brief overview of the relevance of new findings about the Fibonacci Life Chart Method (FLCM) for understanding synchronicity. The FLCM is reviewed first, including an exposition of the g... This article aims to provide a brief overview of the relevance of new findings about the Fibonacci Life Chart Method (FLCM) for understanding synchronicity. The FLCM is reviewed first, including an exposition of the golden section model, and elaboration of a new harmonic model. The two models are then compared to illuminate several strengths and weaknesses in connection with the following four major criteria regarding synchronicity: explanatory adequacy;predictability of future synchronicities;simplicity of the model;and generalizability to other branches of knowledge. The review indicates that both models appear capable of simulating nonlinear and fractal dynamics. Hybrid approaches that combine both models are feasible and necessary for projects that aim to experimentally address synchronicity. 展开更多
关键词 SYNCHRONICITY Dynamical Systems Brain Dynamics FIBONACCI Life chart Method GOLDEN Section model Harmonic model
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Memory-Type Control Charts Through the Lens of Cost Parameters
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作者 Sakthiseswari Ganasan You Huay Woon +1 位作者 Zainol Mustafa Dadasaheb G.Godase 《Intelligent Automation & Soft Computing》 SCIE 2023年第4期1-10,共10页
A memory-type control chart utilizes previous information for chart construction.An example of a memory-type chart is an exponentially-weighted moving average(EWMA)control chart.The EWMA control chart is well-known an... A memory-type control chart utilizes previous information for chart construction.An example of a memory-type chart is an exponentially-weighted moving average(EWMA)control chart.The EWMA control chart is well-known and widely employed by practitioners for monitoring small and moderate process mean shifts.Meanwhile,the EWMA median chart is robust against outliers.In light of this,the economic model of the EWMA and EWMA median control charts are commonly considered.This study aims to investigate the effect of cost parameters on the out-of-control average run lengthðARL_(1)Þin implementing EWMA and EWMA median control charts.The economic model was used to compute the ARL_(1) parameter.The 14 input parameters were identified and the analysis was carried out based on the one-parameter-at-a-time basis.When the input parameters change based on a predetermined percentage,the ARL_(1) is affected.According to the results of the EWMA chart,nine input parameters had an effect andfive input parameters had no effect on the ARL_(1) parameter.Further,only seven of the 14 input parameters had an effect on the ARL_(1) of the EWMA median chart.However,the effect of each input parameter on the ARL_(1) was different.Moreover,the ARL_(1) for the EWMA median chart was smaller than the EWMA chart.This analysis is crucial to observe and determine the input parameters that have a significant impact on the ARL_(1) of the EMWA and EWMA median control charts.Hence,practitioners can obtain an overview of the influence of the input parameters on the ARL_(1) when implementing the EWMA and EWMA median control charts. 展开更多
关键词 Economic model average run length memory-type control chart cost parameters statistical quality control
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An Approximate Numerical Methods for Mathematical and Physical Studies for Covid-19 Models
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作者 Hammad Alotaibi Khaled A.Gepreel +1 位作者 Mohamed S.Mohamed Amr M.S.Mahdy 《Computer Systems Science & Engineering》 SCIE EI 2022年第9期1147-1163,共17页
The advancement in numerical models of serious resistant illnesses is a key research territory in different fields including the nature and the study of disease transmission.One of the aims of these models is to compr... The advancement in numerical models of serious resistant illnesses is a key research territory in different fields including the nature and the study of disease transmission.One of the aims of these models is to comprehend the elements of conduction of these infections.For the new strain of Covid-19(Coronavirus),there has been no immunization to protect individuals from the virus and to forestall its spread so far.All things being equal,control procedures related to medical services,for example,social distancing or separation,isolation,and travel limitations can be adjusted to control this pandemic.This article reveals some insights into the dynamic practices of nonlinear Coronavirus models dependent on the homotopy annoyance strategy(HPM).We summon a novel sign stream chart that is utilized to depict the Coronavirus model.Through the numerical investigations,it is uncovered that social separation of the possibly tainted people who might be conveying the infection and the healthy virus-free people can diminish or interrupt the spread of the infection.The mathematical simulation results are highly concurrent with the statistical forecasts.The free balance and dependability focus for the Coronavirus model is discussed and the presence of a consistently steady arrangement is demonstrated. 展开更多
关键词 Covid-19 model optimal control existence of uniformly stable signal stream chart homotopy perturbation technique
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Characteristics of Tides in the Red Sea Region, a Numerical Model Study
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作者 Fawaz Madah Roberto Mayerle +1 位作者 Gerd Bruss Joaquim Bento 《Open Journal of Marine Science》 2015年第2期193-209,共17页
In this work, a two-dimensional numerical model based on Delft3D modelling system was setup to study the tidal characteristics of the Red Sea. Besides that, analyses of available observed time series of surface elevat... In this work, a two-dimensional numerical model based on Delft3D modelling system was setup to study the tidal characteristics of the Red Sea. Besides that, analyses of available observed time series of surface elevations were carried out. Sensitivity analyses of the numerical model were carried out by testing different model parameters aiming at selecting optimal settings. The model performance was evaluated against available time series of surface elevation observations. RMS error was found to vary from 0.03 to 0.1 meter, while the ADM values range from 0.02 to 0.05 meter. On the whole, the model is able to reproduce the tidal wave in the Red Sea, reflecting a consistent level of agreement with the observations and previous works. The model results suggest that the semidiurnal tidal waves play a major role in the region except in the central part of the Red Sea where amphidromic system exists. Major semidiurnal and diurnal tidal constituents were computed to generate co-charts and form factor. The results have revealed that the distribution of the co-charts of the major semidiurnal constituents M2, N2, and S2 show the existence of anticlockwise amphidromic system in the central part of the Red Sea at about 19.5°N, north of the Strait of Bab el Mandeb at 13.5°N and in the Gulf of Suez. The chart of the diurnal tidal constituent K1 showed a single counterclockwise system in the southern part of the Red Sea centred around 15.5°N. The form factor chart shows the appearance of diurnal character in the central part of the basin and the northern end of the strait. The hydrodynamics patterns under spring and neap tidal conditions were also analysed (during flood and ebb conditions). Model results showed that currents generally are weak and strongest currents are present in the strait of Bab el Mandeb and Gulf of Suez. 展开更多
关键词 RED SEA Delft3D modelling SYSTEM Amphidromic SYSTEM Co-charts
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包含多维度评价指标的实验设备定量优化配置模型设计 被引量:1
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作者 赵建勇 陈磊磊 +3 位作者 吴敏 年珩 于彦雪 孙丹 《实验室研究与探索》 北大核心 2025年第3期195-200,共6页
针对现阶段实验室建设规划主要以经验法为主、在实验设备配置上缺乏量化建模分析方法的缺点,提出了一种适用于教学实验设备定量规划的多目标优化配置方法。建立的基于改进雷达图的优化配置模型,得到投资成本、运维成本、学生覆盖面、学... 针对现阶段实验室建设规划主要以经验法为主、在实验设备配置上缺乏量化建模分析方法的缺点,提出了一种适用于教学实验设备定量规划的多目标优化配置方法。建立的基于改进雷达图的优化配置模型,得到投资成本、运维成本、学生覆盖面、学生受益率、设备利用率等多个实验室规划建设中重要评价目标综合最优的实验设备配置结果。通过配置与经验法对比结果表明:除运维成本略有增加外,在学生覆盖面、学生受益指数、设备利用率等方面均有明显优势;其多目标优化模型的综合指标取得了最优规划效果。该模型对高校的实验室建设规划提供了参考借鉴。 展开更多
关键词 新工科 实验室规划 多层级实验装置 优化配置 雷达图模型
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Establishment of an initial water production evaluation chart for the gas province in the East China Sea
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作者 Lu Kefeng Cai Hua +3 位作者 Wang Li Shi Meixue He Xianke Fan Hongjun 《Natural Gas Industry B》 2019年第6期580-587,共8页
In order to reveal the reasons for the differences in initial water production characteristics of gas wells in different regions of the East China Sea Basin and to screen favorable targets for low-permeability reservo... In order to reveal the reasons for the differences in initial water production characteristics of gas wells in different regions of the East China Sea Basin and to screen favorable targets for low-permeability reservoir reconstruction,a calculation method of initial production wateregas ratios at different gas column heights was established by combining gas-water two-phase capillary pressure with J function definition,power function relative permeability model and fractional flow equation.Then based on the experimental data of standard capillary pressure and standard relative permeability in the gas province of the East China Sea,an evaluation chart on initial production wateregas ratio of the East China Sea at different gas column heights was calculated and established.Finally,the evaluation chart was validated by using the data of the tested or commissioned gas wells in the gas reservoirs of the East China Sea,and the physical property conditions suitable for reservoir reconstruction of low-permeability gas reservoirs in the East China Sea were determined according to the evaluation chart.The following research results were obtained.First,the evaluation chart established in this paper reflects that the correlation between the parameters is similar to the actual production law and matches well with the actual data,which verifies the correctness and reliability of the chart establishment method and the key parameter calculation method.Second,with the production wateregas ratio less than 1 m3/104 m3 as the screening condition,for the permeability of the low-permeability gas reservoirs(with gas column height of about 50 m)in the west sub-sag,the central uplift belt and the periphery suitable for reservoir reconstruction shall be greater than 0.65 mD,and that of the large low-permeability gas reservoirs(with a gas column height of more than 100 m)in the north of central uplift belt shall be greater than 0.26 mD.Third,there is no gasewater contact in gas reservoirs under the hydrocarbon accumulation conditions of in-situ reservoirs,so the method and the evaluation chart proposed in this paper are not applicable.It is concluded that the method of establishing the initial water production evaluation chart and the method of calculating the key parameters proposed in this paper can provide meaningful reference for the development and evaluation of other gas fields in China. 展开更多
关键词 China East China Sea Basin Gas reservoir Capillary pressure Relative permeability model Wateregas ratio Evaluation chart Reservoir reconstruction Parameter calculation
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Tool Condition Monitoring Based on Nonlinear Output Frequency Response Functions and Multivariate Control Chart
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作者 Yufei Gui Ziqiang Lang +1 位作者 Zepeng Liu Hatim Laalej 《Journal of Dynamics, Monitoring and Diagnostics》 2023年第4期243-251,共9页
Tool condition monitoring(TCM)is a key technology for intelligent manufacturing.The objective is to monitor the tool operation status and detect tool breakage so that the tool can be changed in time to avoid significa... Tool condition monitoring(TCM)is a key technology for intelligent manufacturing.The objective is to monitor the tool operation status and detect tool breakage so that the tool can be changed in time to avoid significant damage to workpieces and reduce manufacturing costs.Recently,an innovative TCM approach based on sensor data modelling and model frequency analysis has been proposed.Different from traditional signal feature-based monitoring,the data from sensors are utilized to build a dynamic process model.Then,the nonlinear output frequency response functions,a concept which extends the linear system frequency response function to the nonlinear case,over the frequency range of the tooth passing frequency of the machining process are extracted to reveal tool health conditions.In order to extend the novel sensor data modelling and model frequency analysis to unsupervised condition monitoring of cutting tools,in the present study,a multivariate control chart is proposed for TCM based on the frequency domain properties of machining processes derived from the innovative sensor data modelling and model frequency analysis.The feature dimension is reduced by principal component analysis first.Then the moving average strategy is exploited to generate monitoring variables and overcome the effects of noises.The milling experiments of titanium alloys are conducted to verify the effectiveness of the proposed approach in detecting excessive flank wear of solid carbide end mills.The results demonstrate the advantages of the new approach over conventional TCM techniques and its potential in industrial applications. 展开更多
关键词 intelligent manufacturing multivariate control chart Nonlinear Autoregressive with eXogenous Input modelling Nonlinear Output Frequency Response Functions tool condition monitoring
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冠心病患者经皮冠状动脉介入术后主要不良心血管事件发生的影响因素及列线图模型的构建 被引量:4
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作者 桂元 蒋毅 +3 位作者 詹继东 黄沁 张祎 张静 《中国心血管病研究》 2025年第1期29-34,共6页
目的调查冠心病(CHD)患者经皮冠状动脉介入术(PCI)术后主要不良心血管事件(MACE发生的影响因素,并建立有效预测CHD患者PCI术后发生MACE的列线图预测模型并进行验证。方法选取华中科技大学同济医学院附属同济医院2022年1月至2024年8月收... 目的调查冠心病(CHD)患者经皮冠状动脉介入术(PCI)术后主要不良心血管事件(MACE发生的影响因素,并建立有效预测CHD患者PCI术后发生MACE的列线图预测模型并进行验证。方法选取华中科技大学同济医学院附属同济医院2022年1月至2024年8月收治的346例确诊的CHD患者为研究对象,根据7∶3的比例随机分为建模组242例和验证组104例,建模组根据患者是否发生MACE分为发生组(85例)和未发生组(157例)。通过Logistic回归分析筛选CHD患者发生MACE的影响因素;采用R软件及RMS程序包构建CHD患者发生MACE的列线图风险预测模型;采用ROC曲线、校准图形验证模型的区分度以及一致性。结果与未发生组相比,发生组患者B型利钠肽(BNP)、心电图Q-T间期离散度(QTd)、冠状动脉中重度钙化、支架数量≥2个的占比明显升高[(522.19±55.37)ng/L比(449.06±50.24)ng/L、(85.47±9.68)ms比(72.51±8.23)ms、33.82%比19.75%、30.59%比14.01%,均P<0.05)],白蛋白(ALB)、左心室射血分数(LVEF)、左心房内径(LAD)水平明显降低[(32.54±4.49)g/L比(41.59±5.61)g/L、(33.08±4.65)%比(40.25±5.18)%、(42.18±5.24)mm比(49.37±5.36)mm,均P<0.05];BNP(OR=1.023)、ALB(OR=0.708)、QTd(OR=1.290)、LVEF(OR=0.773)、LAD(OR=0.739)、冠状动脉中重度钙化(OR=19.708)均为CHD患者发生MACE的影响因素(P<0.05);构建列线图预测模型预测发生MACE风险的曲线下面积(AUC)为0.955(95%CI0.933~0.977),说明区分度良好,校正曲线趋近于理想曲线,实际值与预测值一致性良好;验证组中,列线图预测MACE发生风险的AUC为0.901(95%CI 0.846~0.957)。结论BNP、ALB、QTd、LVEF、LAD、冠状动脉中重度钙化为CHD患者PCI术后发生MACE的影响因素,进一步成功构建列线图预测模型,经过验证分析该列线图预测模型可有效预测CHD患者PCI术后发生MACE的风险。 展开更多
关键词 冠心病 主要不良心血管事件 影响因素 列线图模型
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航海智能仿真技术及应用研究综述 被引量:1
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作者 刘涛 李瀚熙 +1 位作者 尹勇 刘佳仑 《系统仿真学报》 北大核心 2025年第7期1684-1709,共26页
航海仿真通过构建船舶航行环境和行为模型,模拟不同场景下的船舶响应,用于预判复杂干扰条件下的行为特征。随着计算机图形学、虚拟现实和人工智能技术的发展,尤其是无人船技术的发展,航海仿真技术出现了新的研究内容和应用。介绍了航海... 航海仿真通过构建船舶航行环境和行为模型,模拟不同场景下的船舶响应,用于预判复杂干扰条件下的行为特征。随着计算机图形学、虚拟现实和人工智能技术的发展,尤其是无人船技术的发展,航海仿真技术出现了新的研究内容和应用。介绍了航海仿真技术的研究现状和发展趋势,从典型场景、关键技术和发展趋势三方面对航海仿真技术进行研究综述;剖析了多维电子海图、智能电子海图、船舶运动数学模型、航海模拟器等技术的发展趋势和重点;明确了以“数字孪生”和“虚实融合测试验证”技术为重要发展方向的未来航海智能仿真新趋势。关键技术攻关与产品研发是持续推进航海智能仿真技术发展的基础。该研究为航海智能仿真技术的研究与应用提供了系统参考。 展开更多
关键词 航海仿真 电子海图 船舶运动数学模型 数字孪生 虚实融合测试 航海模拟器
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