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Cosmography of non-interacting ghost and generalized ghost dark energy models in f(Q)gravity
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作者 M Sharif Madiha Ajmal 《Communications in Theoretical Physics》 2025年第4期102-116,共15页
This paper aims to develop non-interacting ghost dark energy and generalized ghost dark energy models within the framework of f(Q)theory using the correspondence scheme.We use pressureless matter and a power-law scale... This paper aims to develop non-interacting ghost dark energy and generalized ghost dark energy models within the framework of f(Q)theory using the correspondence scheme.We use pressureless matter and a power-law scale factor.The cosmic implications of the resulting models are studied through the equation of state parameter and the phase planes.We also check the stability of the reconstructed models through the squared speed of sound parameter.The equation of state parameter exhibits a phantom era,the(ωD-ω'D)-plane indicates a freezing region,while the(r-s)-plane corresponds to the Chaplygin gas model for both models.It is also found that only the generalized ghost dark energy model remains stable throughout cosmic evolution.We conclude that our findings align well with current observational data. 展开更多
关键词 cosmological evolution dark energy models f(q)gravity
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Skeletal abnormalities caused by a Connexin43_(R239Q)mutation in a mouse model for autosomal recessive craniometaphyseal dysplasia
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作者 Yasuyuki Fujii Iichiro Okabe +7 位作者 Ayano Hatori Shyam Kishor Sah Jitendra Kanaujiya Melanie Fisher Rachael Norris Mark Terasaki Ernst J.Reichenberger I-Ping Chen 《Bone Research》 2025年第2期370-383,共14页
Craniometaphyseal dysplasia(CMD),a rare craniotubular disorder,occurs in an autosomal dominant(AD)or autosomal recessive(AR)form.CMD is characterized by hyperostosis of craniofacial bones and metaphyseal flaring of lo... Craniometaphyseal dysplasia(CMD),a rare craniotubular disorder,occurs in an autosomal dominant(AD)or autosomal recessive(AR)form.CMD is characterized by hyperostosis of craniofacial bones and metaphyseal flaring of long bones.Many patients with CMD suffer from neurological symptoms.The pathogenesis of CMD is not fully understood. 展开更多
关键词 connexin r q mutation mouse model hyperostosis craniofacial bones metaphyseal flaring craniometaphyseal dysplasia skeletal abnormalities autosomal recessive craniotubular disorderoccurs
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基于深度Q-learning算法的智能电网管控模型研究
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作者 王筠 李志鹏 +2 位作者 项旭 张军堂 石雷波 《自动化技术与应用》 2026年第2期54-57,142,共5页
设计基于深度Q-learning算法的智能电网管控模型,将可验证声明(verifiable credential, VC)和分布式数字身份(decentralized identity, DID)作为应用程序身份凭证与软件定义网络(software-defined networking, SDN)控制器,结合动态信任... 设计基于深度Q-learning算法的智能电网管控模型,将可验证声明(verifiable credential, VC)和分布式数字身份(decentralized identity, DID)作为应用程序身份凭证与软件定义网络(software-defined networking, SDN)控制器,结合动态信任评估算法与基于属性的访问控制策略,构建基于区块链的智能电网分布式SDN管控模型。在资源分配、网络拓扑动态变化以及安全威胁不断演变的情况下,实施基于区块链的分布式SDN网络的优化。实验测试结果表明,设计方法在通过深度Q-learning优化模型后累积奖励明显大幅增加,在多种安全性能方面表现出色,能够清除恶意域,确保网络环境的安全。 展开更多
关键词 SDN控制器 分布式SDN网络 深度q-learning算法 区块链 智能电网管控模型
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基于认知诊断DINA模型的Q矩阵优化:一种结合样本筛选与假设检验的新策略 被引量:2
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作者 李波 胡誉骞 +1 位作者 章勇 田怡 《华中师范大学学报(自然科学版)》 北大核心 2025年第1期111-124,共14页
该文创新性地提出了一种基于DINA模型的Q矩阵修正策略——SHT法,并借助蒙特卡洛模拟技术,将其与现有同类方法进行深入对比,以全面评估其可行性与精确性.该方法具有下述3个方面优势.1)高效修正与稳健性验证:SHT法在不同水平的作答错误率... 该文创新性地提出了一种基于DINA模型的Q矩阵修正策略——SHT法,并借助蒙特卡洛模拟技术,将其与现有同类方法进行深入对比,以全面评估其可行性与精确性.该方法具有下述3个方面优势.1)高效修正与稳健性验证:SHT法在不同水平的作答错误率下均展现出了卓越的修正效能,显著提升了Q矩阵的精确度;2)小样本与大样本环境的双重优势:与国内外同类研究成果相比,SHT法在小样本场景下尤为突出,其稳健性和性能优势在面临高作答失误率时更加显著;3)复杂数据集下的显著优势:在实证数据分析中,SHT法不仅提高了认知诊断模型的拟合能力,更在处理数据维度复杂、样本相对受限的数据集时,展现出相比其他算法更为明显的优势. 展开更多
关键词 认知诊断 q矩阵修正 DINA模型 假设检验 δ法 γ法
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基于多模态融合大模型架构Agri-QA Net的作物知识问答系统 被引量:3
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作者 吴华瑞 赵春江 李静晨 《智慧农业(中英文)》 2025年第1期1-10,共10页
[目的/意义]随着农业信息化和智能化的快速发展,多模态人机交互技术在农业领域的重要性日益凸显。本研究提出了一种基于多模态融合的大模型架构Agri-QA Net,旨在针对甘蓝作物的农业知识,设计多模态专业问答系统。[方法]该模型通过整合... [目的/意义]随着农业信息化和智能化的快速发展,多模态人机交互技术在农业领域的重要性日益凸显。本研究提出了一种基于多模态融合的大模型架构Agri-QA Net,旨在针对甘蓝作物的农业知识,设计多模态专业问答系统。[方法]该模型通过整合文本、音频和图片数据,利用预训练的BERT(Bidirectional Encoder Representations from Transformers)模型提取文本特征,声学模型提取音频特征,以及卷积神经网络提取图像特征,并采用基于Transformer的融合层来整合这些特征。此外,引入跨模态注意力机制和领域自适应技术,增强了模型对农业领域专业知识的理解和应用能力。本研究通过收集和预处理甘蓝种植相关的多模态数据,训练并优化了AgriQA Net模型。[结果和讨论]实验评估表明,该模型在甘蓝农业知识问答任务上表现出色,相较于传统的单模态或简单多模态模型,具有更高的准确率和更好的泛化能力。在多模态输入的支持下,其准确率达到了89.5%,精确率为87.9%,召回率为91.3%,F_(1)值为89.6%,均显著高于单一模态模型。[结论]案例研究展示了Agri-QA Net在实际农业场景中的应用效果,证明了其在帮助农民解决实际问题中的有效性。未来的工作将探索模型在更多农业场景中的应用,并进一步优化模型性能。 展开更多
关键词 多模态融合 人机交互 农业知识问答 甘蓝作物 大语言模型
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社会学习视角下知识问答平台用户转移意愿研究——基于PSL-SEM和FsQCA方法的实证
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作者 沈旺 王禹心 +2 位作者 梁世豪 冯欣 李贺 《情报科学》 北大核心 2025年第9期148-160,共13页
【目的/意义】本文基于社会学习理论及推拉锚定模型探究用户从免费知识问答平台向付费知识问答平台进行转移的意愿,对深入理解用户转移动机以及促进付费知识平台的可持续发展具有重要意义。【方法/过程】从社会学习的视角出发,结合推拉... 【目的/意义】本文基于社会学习理论及推拉锚定模型探究用户从免费知识问答平台向付费知识问答平台进行转移的意愿,对深入理解用户转移动机以及促进付费知识平台的可持续发展具有重要意义。【方法/过程】从社会学习的视角出发,结合推拉锚定模型构建理论假设模型,利用结构方程(SEM)以及模糊集定性比较分析(fsQCA)方法,探究影响用户从免费知识问答平台转向付费知识问答平台的因素及其组态。【结果/结论】研究结果表明用户在知识付费的转移过程中会从他人的反馈意见、行为以及行为结果中进行学习。所构成的组态路径共有五种,在组合效应型组态路径中用户在决策过程中会参考其他用户的意见。在创新-拉动型组态路径中高创新性的个体更易接受新鲜事物,同时用户会从积极口碑中进行学习形成正向的反馈,从而加强他们的转移意愿。在辅助效应型组态路径中用户在转移过程中会受到一定程度的锚定效应的影响。深化了对提问者转移意愿及其背后动因的理解,并为付费知识问答平台提出了的许多可行性建议。【创新/局限】本研究探讨了提问者转移意愿及其背后动因并提出相应策略。通过fsQCA探究变量间的复杂关系,具有一定的创新性。 展开更多
关键词 知识付费 知识问答平台 转移意愿 社会学习理论 PPM模型
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Chaos game representation(CGR)-walk model for DNA sequences 被引量:4
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作者 高洁 徐振源 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第1期370-376,共7页
Chaos game representation (CGR) is an iterative mapping technique that processes sequences of units, such as nucleotides in a DNA sequence or amino acids in a protein, in order to determine the coordinates of their ... Chaos game representation (CGR) is an iterative mapping technique that processes sequences of units, such as nucleotides in a DNA sequence or amino acids in a protein, in order to determine the coordinates of their positions in a continuous space. This distribution of positions has two features: one is unique, and the other is source sequence that can be recovered from the coordinates so that the distance between positions may serve as a measure of similarity between the corresponding sequences. A CGR-walk model is proposed based on CGR coordinates for the DNA sequences. The CGR coordinates are converted into a time series, and a long-memory ARFIMA (p, d, q) model, where ARFIMA stands for autoregressive fractionally integrated moving average, is introduced into the DNA sequence analysis. This model is applied to simulating real CGR-walk sequence data of ten genomic sequences. Remarkably long-range correlations are uncovered in the data, and the results from these models are reasonably fitted with those from the ARFIMA (p, d, q) model. 展开更多
关键词 CGR-walk model DNA sequence LONG-MEMORY ARFIMA(p d q model
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基于深度Q网络算法的空天地边缘计算网络资源分配方法
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作者 李新春 孙鹤源 许驰 《吉林大学学报(工学版)》 北大核心 2025年第7期2418-2424,共7页
由于卫星、无人机和地面站位置不断变化,导致空天地边缘计算网络链路不固定,且网络需要快速响应用户请求,对吞吐量与实时性的要求较高,增加了网络资源分配的难度。对此,本文提出基于深度Q网络算法的空天地边缘计算网络资源分配方法。首... 由于卫星、无人机和地面站位置不断变化,导致空天地边缘计算网络链路不固定,且网络需要快速响应用户请求,对吞吐量与实时性的要求较高,增加了网络资源分配的难度。对此,本文提出基于深度Q网络算法的空天地边缘计算网络资源分配方法。首先,考虑网络拓扑的动态性和资源异构性,建立资源间的通信模型,为资源分配提供基础框架;然后,基于最大吞吐量设计资源分配目标函数,并利用马尔科夫决策模型表述目标函数,将资源分配问题转化为序列决策问题,便于在动态变化的网络环境中作出决策;最后,基于深度Q网络算法求解目标函数,通过强化学习的方式,使算法能够通过与环境的交互学习到最优的资源分配策略,适应网络的实时性和动态性。实验结果表明:应用该方法后,网络累计回报较高,资源任务平均能耗降低,说明该方法实际可行。 展开更多
关键词 空天地一体化网络 深度q网络算法 边缘计算 资源分配 马尔科夫决策模型
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Chaos game representation walk model for the protein sequences 被引量:3
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作者 高洁 蒋丽丽 徐振源 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第10期4571-4579,共9页
A new chaos game representation of protein sequences based on the detailed hydrophobic-hydrophilic (HP) model has been proposed by Yu et al (Physica A 337(2004) 171). A CGR-walk model is proposed based on the ne... A new chaos game representation of protein sequences based on the detailed hydrophobic-hydrophilic (HP) model has been proposed by Yu et al (Physica A 337(2004) 171). A CGR-walk model is proposed based on the new CGR coordinates for the protein sequences from complete genomes in the present paper. The new CCR coordinates based on the detailed HP model are converted into a time series, and a long-memory ARFIMA(p, d, q) model is introduced into the protein sequence analysis. This model is applied to simulating real CCR-walk sequence data of twelve protein sequences. Remarkably long-range correlations are uncovered in the data and the results obtained from these models are reasonably consistent with those available from the ARFIMA(p, d, q) model. 展开更多
关键词 chaos game representation CGR-walk model protein sequence long-memory ARFIMA(p d q model autocorrelation function
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含LCC-HVDC的交直流系统D-Q建模与潮流计算
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作者 刘闯 王锡龙 +1 位作者 任洺瑶 陈俊睿 《电力自动化设备》 北大核心 2025年第5期145-152,共8页
针对包含基于电网换相换流器的高压直流输电(LCC-HVDC)的交直流系统,提出基于D-Q电网络的统一迭代潮流算法。推导考虑交直流互联的直流网络稳态模型和D-Q电网络稳态模型;根据电网换相换流器(LCC)的相量模型和功率方程,建立基于D-Q电网络... 针对包含基于电网换相换流器的高压直流输电(LCC-HVDC)的交直流系统,提出基于D-Q电网络的统一迭代潮流算法。推导考虑交直流互联的直流网络稳态模型和D-Q电网络稳态模型;根据电网换相换流器(LCC)的相量模型和功率方程,建立基于D-Q电网络的LCC稳态模型。该算法采用网络电气量为变量,通过对PQ节点和直流节点列写基于电流关系的潮流方程使潮流方程组雅可比矩阵的非零元素大多为常数,以提升计算的速度和稳定性,降低对初值的敏感度。在改进的IEEE 14、IEEE 39节点系统中,将所提算法与传统算法进行对比,结果表明,所提算法具有良好的计算速度、稳定的收敛性及对交流电压初值较低的敏感度。 展开更多
关键词 潮流计算 统一迭代 LCC-HVDC D-q电网络 稳态模型
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Bayesian Estimation for the Order of INAR(q)Model 被引量:1
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作者 MIAO GUAN-HONG WANG DE-HUI 《Communications in Mathematical Research》 CSCD 2016年第4期325-331,共7页
In this paper, we consider the problem of determining the order ofINAR(Q) model on the basis of the Bayesian estimation theory. The Bayesian es-timator for the order is given with respect to a squared-error loss fu... In this paper, we consider the problem of determining the order ofINAR(Q) model on the basis of the Bayesian estimation theory. The Bayesian es-timator for the order is given with respect to a squared-error loss function. The consistency of the estimator is discussed. The results of a simulation study for the estimation method are presented. 展开更多
关键词 INAR(q model Bayesian estimation squared-error loss function con-sistency
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Hidden Markov model based epileptic seizure detection using tunable Q wavelet transform 被引量:2
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作者 Deba Prasad Dash Maheshkumar H Kolekar 《The Journal of Biomedical Research》 CAS CSCD 2020年第3期170-179,共10页
Epilepsy is one of the most prevalent neurological disorders affecting 70 million people worldwide.The present work is focused on designing an efficient algorithm for automatic seizure detection by using electroenceph... Epilepsy is one of the most prevalent neurological disorders affecting 70 million people worldwide.The present work is focused on designing an efficient algorithm for automatic seizure detection by using electroencephalogram(EEG) as a noninvasive procedure to record neuronal activities in the brain.EEG signals' underlying dynamics are extracted to differentiate healthy and seizure EEG signals.Shannon entropy,collision entropy,transfer entropy,conditional probability,and Hjorth parameter features are extracted from subbands of tunable Q wavelet transform.Efficient decomposition level for different feature vector is selected using the Kruskal-Wallis test to achieve good classification.Different features are combined using the discriminant correlation analysis fusion technique to form a single fused feature vector.The accuracy of the proposed approach is higher for Q=2 and J=10.Transfer entropy is observed to be significant for different class combinations.Proposed approach achieved 100% accuracy in classifying healthy-seizure EEG signal using simple and robust features and hidden Markov model with less computation time.The proposed approach efficiency is evaluated in classifying seizure and non-seizure surface EEG signals.The system has achieved 96.87% accuracy in classifying surface seizure and nonseizure EEG segments using efficient features extracted from different J level. 展开更多
关键词 ELECTROENCEPHALOGRAM EPILEPSY SEIZURE tunable q wavelet transform ENTROPY hidden Markov model
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Arnol'd's Second Nonlinear Stability Theorem for General Multilayer Quasi-geostrophic Model 被引量:7
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作者 刘永明 穆穆 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1994年第1期36-42,共7页
Arnol'd's second nonlinear stability criterion for motions governed by a general multilayer quasi-geostrophic model is established. The model allows arbitrary density jumps and layer thickness, and at the top ... Arnol'd's second nonlinear stability criterion for motions governed by a general multilayer quasi-geostrophic model is established. The model allows arbitrary density jumps and layer thickness, and at the top and the bottom of the nuid, the boundary condition is either free or rigid. The criterion is obtained by the establishment of the upper bounds of disturbance energy and potential enstrophy in terms of the initial disturbance field. 展开更多
关键词 Nonlinear stability Multi-layer q-G model
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中碳高硅Q&P钢马氏体相变动力学 被引量:4
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作者 刘曼 周明星 +2 位作者 陈振业 尹伟凡 徐光 《钢铁》 北大核心 2025年第3期117-124,共8页
目前常用经典的K-M(Koistinen-Marburger)模型描述钢的马氏体相变动力学,但模型的准确性与钢种成分密切相关。基于不同冷却速率的淬火试验,采用膨胀法、金相法研究了常见中碳高硅淬火-配分(Q&P)钢的马氏体相变动力学规律,并基于传统... 目前常用经典的K-M(Koistinen-Marburger)模型描述钢的马氏体相变动力学,但模型的准确性与钢种成分密切相关。基于不同冷却速率的淬火试验,采用膨胀法、金相法研究了常见中碳高硅淬火-配分(Q&P)钢的马氏体相变动力学规律,并基于传统K-M模型建立了适用于中碳高硅Q&P钢的改进马氏体相变动力学模型,并对其进行了验证。结果表明,不同冷却速率下,中碳高硅Q&P钢的马氏体相变动力学曲线呈“S”形,而不是“C”形,相变过程可分为开始相变的加速期、中间相变的高速期和最后相变的减速期,这可能是马氏体的自回火现象引起的。此外,靠近马氏体相变开始温度形成的马氏体较为粗大,此时温度较高,碳从过饱和马氏体板条扩散到周围未转化的奥氏体中,奥氏体碳富集增加了残余奥氏体的稳定性,使得过冷度需要进一步增加才能继续发生马氏体相变,从而降低了残余奥氏体的马氏体相变开始温度。马氏体相变动力学方程指数β为1~2的常数。β值对淬火温度的敏感性取决于钢的碳含量。碳含量升高时,β值对淬火温度的敏感性显著降低,基本可以忽略。速率参数α为淬火温度的3次多项式函数,随着冷却速率的增加,速率参数α逐渐降低,这表明马氏体相变可能是一个与时间有关的相变;而方程指数β逐渐增加,这与奥氏体塑性调节对马氏体相变的抑制作用有关。改进K-M模型考虑了马氏体相变的瞬时动力学特性,与试验数据的匹配度较传统K-M模型更好。 展开更多
关键词 中碳高硅q&P钢 马氏体相变 动力学模型 速率参数 方程指数 改进K-M模型 高级钢 TRIP效应
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MODELING v_P AND Q ON EXPLOSION SEISMOLOGY DATA IN NE TIBET
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作者 A. Galvé 1, A. Hirn 1, J. Gallart 2, Jiang Mei 3, Wang Youxue 3 2 IJA, CSIC, calle Lluis Sole i Sabaris, Barcelona 08028, Spain 3 Chinese Academy of Geological Sciences, Baiwanzhuang Roa 《地学前缘》 EI CAS CSCD 2000年第S1期331-331,共1页
A Sino\|French refraction\|reflection experiment was conducted in October 1998 in the northeastern edge of the Tibetan Plateau from the Qiang Tang through the north Kunlun block.The successive wide\|angle reflection t... A Sino\|French refraction\|reflection experiment was conducted in October 1998 in the northeastern edge of the Tibetan Plateau from the Qiang Tang through the north Kunlun block.The successive wide\|angle reflection traveltime curves are modeled trying to keep the minimum structure. First results obtained along this 700km transect, show the contrast of crustal structure between the three blocks crossed and the state of the crustal material.North of the Kunlun suture, a change of the Moho depth appears from the Qaidam basin, 55km, to the south approaching the Kunlun range, 65km. But the main crustal characteristic is a great thickness of upper crustal material and the lack of lower crust. This implies a crustal average velocity of 6 2km/s, which is much lower than the worldwide average of 6 45km/s. Interpretations of this crustal column may consider, assuming the crust had been normal that while its upper part thickened the lower one was transported away, underthrust to the south or to depth. Alternatively the velocity in the lower crust may have been changed by metamorphism. 展开更多
关键词 V p q modelING SEISMOLOGY NE TIBET
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TESTING OF CORRELATION AND HETEROSCEDASTICITY IN NONLINEAR REGRESSION MODELS WITH DBL(p,q,1) RANDOM ERRORS
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作者 刘应安 韦博成 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期613-632,共20页
Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (K... Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (Kantz and Schreiber (1997)). Tsai (1986) introduced a composite test for autocorrelation and heteroscedasticity in linear models with AR(1) errors. Liu (2003) introduced a composite test for correlation and heteroscedasticity in nonlinear models with DBL(p, 0, 1) errors. Therefore, the important problems in regression model axe detections of bilinearity, correlation and heteroscedasticity. In this article, the authors discuss more general case of nonlinear models with DBL(p, q, 1) random errors by score test. Several statistics for the test of bilinearity, correlation, and heteroscedasticity are obtained, and expressed in simple matrix formulas. The results of regression models with linear errors are extended to those with bilinear errors. The simulation study is carried out to investigate the powers of the test statistics. All results of this article extend and develop results of Tsai (1986), Wei, et al (1995), and Liu, et al (2003). 展开更多
关键词 DBL(p q 1) random errors nonlinear regression models score test HETEROSCEDASTICITY CORRELATION
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High-precision Q modeling and Q migration technology and its applications in loess plateau regions
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作者 Xu Wei Liu Hong-Xing +4 位作者 Mi Hong-Gang Zhang Bing Guo Jun-Chao Ge Yong You Jun 《Applied Geophysics》 SCIE CSCD 2024年第4期835-847,882,共14页
The propagation of seismic waves in viscous media,such as the loess plateau and shallow gas regions,alters their amplitude,frequency,and phase due to absorption attenuation,resulting in reductions in the resolution an... The propagation of seismic waves in viscous media,such as the loess plateau and shallow gas regions,alters their amplitude,frequency,and phase due to absorption attenuation,resulting in reductions in the resolution and fidelity of seismic profiles and the inaccurate identification of subtle structure and lithology.Q modeling and Q migration techniques proposed in this paper are used to compensate for the energy and frequency attenuation of seismic waves,obtain high-quality depth imaging results,and further enhance structural imaging to address the aforementioned problem.First,various prior information is utilized to construct an initial Q model.Q tomography techniques are employed to further optimize the precision of the initial Q model and build a high-precision Q model.Subsequently,Q prestack depth migration technology is employed to compensate for absorption and attenuation in the three-dimensional space along the seismic wave propagation path and correct the travel times,realizing the purposes of amplitude compensation,frequency recovery,and phase correction,which can help improve the wave group characteristics while enhancing the resolution.Model data and practical application results demonstrate that high-precision Q modeling and Q migration techniques can substantially improve the imaging quality of underground structures and formations in the loess plateau region with extremely complex surface and near-surface conditions.The resolution and fidelity of seismic data,as well as the capability to identify reservoirs,can be improved using these techniques. 展开更多
关键词 absorption compensation q modeling q tomography inversion q migration amplitude preserved loess plateau region
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Geometric Properties of AR(q) Nonlinear Regression Models
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作者 LIUYing-ar WEIBo-cheng 《Chinese Quarterly Journal of Mathematics》 CSCD 2004年第2期146-154,共9页
This paper is devoted to a study of geometric properties of AR(q) nonlinear regression models. We present geometric frameworks for regression parameter space and autoregression parameter space respectively based on th... This paper is devoted to a study of geometric properties of AR(q) nonlinear regression models. We present geometric frameworks for regression parameter space and autoregression parameter space respectively based on the weighted inner product by fisher information matrix. Several geometric properties related to statistical curvatures are given for the models. The results of this paper extended the work of Bates & Watts(1980,1988)[1.2] and Seber & Wild (1989)[3]. 展开更多
关键词 nonlinear regression model AR(q) errors geometric framework statistical curvature Fisher information matrix
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Short-Term Sinusoidal Modeling of an Oriental Music Signal by Using CQT Transform
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作者 Lhoucine Bahatti Mimoun Zazoui +1 位作者 Omar Bouattane Ahmed Rebbani 《Journal of Signal and Information Processing》 2013年第1期51-56,共6页
In this paper, we propose a method for characterizing a musical signal by extracting a set of harmonic descriptors reflecting the maximum information contained in this signal. We focus our study on a signal of orienta... In this paper, we propose a method for characterizing a musical signal by extracting a set of harmonic descriptors reflecting the maximum information contained in this signal. We focus our study on a signal of oriental music characterized by its richness in tone that can be extended to 1/4 tone, taking into account the frequency and time characteristics of this type of music. To do so, the original signal is slotted and analyzed on a window of short duration. This signal is viewed as the result of a combined modulation of amplitude and frequency. For this result, we apply short-term the non-stationary sinusoidal modeling technique. In each segment, the signal is represented by a set of sinusoids characterized by their intrinsic parameters: amplitudes, frequencies and phases. The modeling approach adopted is closely related to the slot window;therefore great importance is devoted to the study and the choice of the kind of the window and its width. It must be of variable length in order to get better results in the practical implementation of our method. For this purpose, evaluation tests were carried out by synthesizing the signal from the estimated parameters. Interesting results have been identified concerning the comparison of the synthesized signal with the original signal. 展开更多
关键词 ORIENTAL Music Signal Short Time FOURIER TRANSFORM Constant q TRANSFORM Modulation Sinusoidal modeling Weighting Window 1/4 TONE
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Modelling of passively Q-switched lasers with intracavity Raman conversion
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作者 苏富芳 张行愚 +5 位作者 王青圃 常军 贾鹏 李述涛 张晓磊 丛振华 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第11期3370-3376,共7页
We present a model of passively Q-switched Raman lasers by utilizing the rate equations. The intracavity fun-damental photon density, Raman photon density and the initial population-inversion density of the gain mediu... We present a model of passively Q-switched Raman lasers by utilizing the rate equations. The intracavity fun-damental photon density, Raman photon density and the initial population-inversion density of the gain medium are assumed to be of Gaussian spatial distributions. These rate equations are normalized by introducing some synthetic parameters and solved numerically, and a group of general curves are generated. Prom these curves we can understand the dependence of the Raman laser pulse characteristics on the parameters about the pumping, the gain medium, the Raman medium and the resonator. An illustrative calculation for a passively Q-switched Nd^3+:GdVO4 self-Raman laser is presented to demonstrate the usage of the curves and related formulas. 展开更多
关键词 intracavity Raman lasers passively q-switched rate equation numerical modelling
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