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基于R-S分解的混流式水轮机偏负荷尾水管涡带湍动能特性分析
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作者 黎志兴 庄建忠 +3 位作者 陈钰林 廖恒 董延春 冯建军 《水电能源科学》 北大核心 2026年第2期190-195,共6页
针对部分负荷工况下混流式水轮机尾水管涡带失稳问题,基于Liutex刚性涡量分解(R-S分解)与湍动能输运方程,揭示了尾水管涡带剪切涡量驱动湍动能的物理机制。结果表明,随着负荷的降低,尾水管内刚性涡量分布由尖峰向宽峰转变,涡核位置偏移... 针对部分负荷工况下混流式水轮机尾水管涡带失稳问题,基于Liutex刚性涡量分解(R-S分解)与湍动能输运方程,揭示了尾水管涡带剪切涡量驱动湍动能的物理机制。结果表明,随着负荷的降低,尾水管内刚性涡量分布由尖峰向宽峰转变,涡核位置偏移明显;剪切涡量通过速度梯度驱动湍动能生成,在尾水管内形成圆桶状剪切层,负荷降低时圆桶状剪切涡区域桶直径增大,剪切涡量分布的双峰间距增大,导致湍动能生成区扩展并加剧流动不稳定性。研究结果揭示了尾水管涡带涡结构与湍动能产生的耦合过程,发现螺旋涡带引发的湍动能与剪切涡量分布形态密切相关,为水轮机宽负荷运行优化及涡带的主动控制提供了理论支撑。 展开更多
关键词 混流式水轮机 尾水管涡带 r-s分解 湍流动能
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基于UPLC-MS/MS技术的(R/S)-2-(2-羟基丙酰氨基)-5-三氟甲基苯甲酸大鼠体内组织分布研究
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作者 高若芳 刘露露 +3 位作者 何丽娟 于治国 赵云丽 龙猜 《沈阳药科大学学报》 2026年第1期87-93,100,共8页
目的建立超高效液相色谱串联质谱法测定大鼠各组织中(R/S)-2-(2-羟基丙酰氨基)-5-三氟甲基苯甲酸[(R/S)-2-(2-hydroxypropanamido)-5-trifluoromethylbenzoic acid,R-/S-HFBA]浓度的方法,研究并比较(R/S)-HFBA在大鼠体内的组织分布特征... 目的建立超高效液相色谱串联质谱法测定大鼠各组织中(R/S)-2-(2-羟基丙酰氨基)-5-三氟甲基苯甲酸[(R/S)-2-(2-hydroxypropanamido)-5-trifluoromethylbenzoic acid,R-/S-HFBA]浓度的方法,研究并比较(R/S)-HFBA在大鼠体内的组织分布特征。方法SD大鼠单次灌胃给药后分别于0.5、3、8 h采取心、肝、脾、肺、肾、胃、小肠、胸腺、肌肉、脂肪等脏器或组织,采用UPLC-MS/MS法测定各组织中HFBA的浓度。结果大鼠单次灌胃给药后0.5 h即可在各组织中检测到HFBA。R-HFBA在各组织中浓度排列顺序为:小肠>胃>肾>肺>心>肝>脂肪>脾>胸腺>肌肉;S-HFBA在各组织中浓度排列顺序为:小肠>胃>肾>肝>肺>心>脾>脂肪>胸腺>肌肉。结论R/S-HFBA在大鼠体内分布广泛且迅速,R-HFBA与S-HFBA在肝脏、肾脏的浓度具有显著差异,推测是由于两者存在立体选择性差异。R/S-HFBA比2-(2-羟基丙酰氨基)-苯甲酸[2-(2-hydroxypropanamido)benzoic acid,HPABA]在大鼠体内保留的时间更长,三氟甲基的引入提高了HFBA的代谢稳定性。 展开更多
关键词 组织分布 超高效液相色谱串联质谱 (r/s)-2-(2-羟基丙酰氨基)-5-三氟甲基苯甲酸 手性药物
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Q345R钢焊缝在湿H_(2)S环境中的腐蚀机理与防护技术研究
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作者 王诗卉 《今日制造与升级》 2026年第1期4-7,共4页
针对石化设备用Q345R钢焊缝在湿H_(2)S环境中易发生氢致开裂和应力腐蚀开裂的问题,通过慢应变速率试验、电化学测试及微观表征,揭示焊缝区腐蚀敏感性高于母材的本质原因。研究表明:热影响区马氏体带(硬度HV280)与焊缝硫偏析(S含量0.015 ... 针对石化设备用Q345R钢焊缝在湿H_(2)S环境中易发生氢致开裂和应力腐蚀开裂的问题,通过慢应变速率试验、电化学测试及微观表征,揭示焊缝区腐蚀敏感性高于母材的本质原因。研究表明:热影响区马氏体带(硬度HV280)与焊缝硫偏析(S含量0.015 wt%)是氢陷阱密集区,HIC裂纹扩展速率达1.2×10^(-6) mm/s;提出焊后消应力处理(590℃×2 h)+焊后热处理+Ni-P镀层技术或焊后热处理+喷涂技术,使SSC门槛值(σ_(SSC))从35%提升至75%,设备寿命延长3倍。 展开更多
关键词 Q345r 焊缝腐蚀 湿H_(2)s 氢致开裂 NI-P镀层 喷涂
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Nuclear heating at the JSI TRIGA reactor:measurements and simulations
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作者 Klemen Ambrožič Hubert Carcreff +4 位作者 Vladimir Radulović Damien Fourmentel Christophe Destouches Nicolas Thiollay Luka Snoj 《Nuclear Science and Techniques》 2026年第4期243-253,共11页
Nuclear heating plays an important aspect in design and deployment of both fission and fusion reactors and experimental devices in terms of cooling requirements. Two experimental campaigns in the framework of a collab... Nuclear heating plays an important aspect in design and deployment of both fission and fusion reactors and experimental devices in terms of cooling requirements. Two experimental campaigns in the framework of a collaboration project between the French Atomic and Alternative Energy Commission(CEA) and Jožef Stefan Institute(JSI), Slovenia, have been performed at the JSI TRIGA reactor for the experimental assessment of nuclear heating in fission and fusion-relevant materials by the differential calorimetry technique, based on the CALMOS and CARMEN differential calorimeters, previously developed at CEA. The results of the first campaign performed at reactor powers between 100 and 250 kW have already been reported, highlighting some measurement difficulties. Therefore, the second campaign was performed at a lower reactor power of 30 kW to overcome these issues. Moreover, a computational analysis of the experiments was performed using the JSIR2S code package to calculate the nuclear heating levels. Both experiments and their reproduction by simulations are described in detail. We present a comparison of the previously reported measured nuclear heating values of the first campaign with the computational results, with consistent underestimation by simulations by 8–35%. We report the experimental and computational results for the second experimental campaign performed at a reactor power of 30 kW. The simulated heating values were in agreement with the measurements within the measured heating uncertainty, with simulated heating 2.7–11.3% lower than the experimental values. 展开更多
关键词 Nuclear heating Differential calorimeter r2s MCNP Eurofer97 TUNGsTEN
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基于S-O-R理论的AR滑雪镜用户采纳影响因素与界面设计研究
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作者 陆宁 刘家玲 岳子钰 《包装工程》 北大核心 2026年第2期523-535,共13页
目的针对AR滑雪镜等智能穿戴产品设计中用户采纳心理洞察不足、设计策略缺乏实证依据的问题,基于“刺激-机体-反应”(S-O-R)理论框架,系统性揭示AR滑雪镜的用户采纳机制并将关键心理路径转化为可操作的界面设计策略。方法首先构建整合... 目的针对AR滑雪镜等智能穿戴产品设计中用户采纳心理洞察不足、设计策略缺乏实证依据的问题,基于“刺激-机体-反应”(S-O-R)理论框架,系统性揭示AR滑雪镜的用户采纳机制并将关键心理路径转化为可操作的界面设计策略。方法首先构建整合成就探索、社交链接、安全感知等外部刺激(S)、感知价值与感觉寻求等机体变量(O),以及采纳意向(R)的理论模型,采用问卷调查与结构方程模型对各路径进行检验并分析感知价值的中介作用和感觉寻求的调节作用。在此基础上提出设计策略,进而构建符合AR视觉人机工学的界面信息架构与视觉规范指导设计。结果成就探索对采纳意向的直接影响最强,社交连接次之,而安全感知需通过感知价值的完全中介间接影响采纳意向。感觉寻求特质显著正向调节感知价值对采纳意向的影响,对高感觉寻求者的解释力更强。基于上述发现设计的界面方案在可用性测试中获得较高评价,其中安全感知维度评分最高,高感觉寻求用户对成就探索功能的评分显著高于低感觉寻求用户。结论构建了从“机制洞察-策略提炼-方案设计-效果验证”的完整设计闭环,揭示了AR滑雪镜用户采纳的心理驱动逻辑与差异化效应,形成了一套面向高风险运动场景的AR界面设计策略体系与实现路径,为AR滑雪镜及同类智能产品的用户导向创新提供理论依据与设计方法支持。 展开更多
关键词 s-O-r理论 Ar滑雪镜 用户采纳意向 界面设计策略
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重症肺炎患儿血清S100A8、sCD163、IL-1R1水平与预后的关系及临床意义
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作者 张重阳 王芳 李平 《现代临床医学》 2026年第1期32-36,共5页
目的:分析重症肺炎患儿血清S100A8、sCD163、IL-1R1水平与预后的关系及临床意义。方法:选取我院2022年2月至2024年8月收治的84例重症肺炎患儿为肺炎组,另选取同期84例健康体检儿童为对照组,比较两组入院时血清S100钙结合蛋白A8(S100A8)... 目的:分析重症肺炎患儿血清S100A8、sCD163、IL-1R1水平与预后的关系及临床意义。方法:选取我院2022年2月至2024年8月收治的84例重症肺炎患儿为肺炎组,另选取同期84例健康体检儿童为对照组,比较两组入院时血清S100钙结合蛋白A8(S100A8)、可溶性血红蛋白清道夫受体(sCD163)、白细胞介素-1受体1(IL-1R1)水平。根据预后情况将肺炎组患儿分为预后良好组(n=62)、预后不良组(n=22),对比不同预后患儿入院时及治疗14 d时的S100A8、sCD163、IL-1R1水平并分析其相关性,判断联合检测对患儿疾病预后的预测价值。结果:肺炎组血清S100A8、sCD163、IL-1R1水平显著高于对照组(P<0.05);入院时、治疗14 d时,预后不良组血清S100A8、sCD163、IL-1R1水平高于预后良好组(P<0.05);血清S100A8、sCD163、IL-1R1水平与患儿疾病预后呈正相关(P<0.05);入院时、治疗14 d时三者联合检测预测患儿预后不良的曲线下面积分别为0.841、0.870;高水平血清S100A8、sCD163、IL-1R1患儿发生预后不良的危险度是低水平患儿的2~4倍(P<0.05)。结论:血清S100A8、sCD163、IL-1R1水平与重症肺炎患儿预后密切相关,三者联合检测可作为评估重症肺炎患儿预后的潜在生物标志物。 展开更多
关键词 s100A8 sCD163 IL-1r1 重症肺炎 疾病预后
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靶向晚期前列腺癌中FOXA1 R219S突变体的药物发现
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作者 林慧 李冬晴 +1 位作者 王文正 郭海洋 《生命的化学》 2026年第1期142-153,共12页
晚期前列腺癌易复发、转移,临床尚无有效治疗手段,亟需发现高效靶向药物。转录因子FOXA1突变在二代抗雄药物耐受的前列腺癌中显著富集,与肿瘤恶性进展高度相关,但目前尚无针对突变型FOXA1蛋白的小分子抑制剂报道。本研究旨在利用虚拟筛... 晚期前列腺癌易复发、转移,临床尚无有效治疗手段,亟需发现高效靶向药物。转录因子FOXA1突变在二代抗雄药物耐受的前列腺癌中显著富集,与肿瘤恶性进展高度相关,但目前尚无针对突变型FOXA1蛋白的小分子抑制剂报道。本研究旨在利用虚拟筛选结合表面等离子共振(surface plasmon resonance,SPR)和IC_(50)、EMSA、RT-qPCR等功能验证实验,筛选FOXA1 R219S突变型蛋白的靶向药物。通过分析临床样本中FOXA1的突变位点及频率,明确热点突变R219S、R219C、R261C、R261G和R261S,并通过药物虚拟筛选发现了一系列针对热点突变的小分子抑制剂。其中,R219S突变在晚期神经内分泌性前列腺癌(neuroendocrine prostate cancer,NEPC)中显著富集,并且该突变促进了前列腺癌恶性增殖及转移。本研究聚焦该突变,首先明确药物靶向FOXA1野生型和R219S突变型蛋白的结合口袋及附近的关键氨基酸位点;为体外验证药物与蛋白质的结合能力,对GST-FOXA1-His蛋白进行异源表达和纯化,并通过SPR实验证实4种药物(咪唑烷基脲、氨磷汀、曲氟尿苷和羟基积雪草苷)选择性结合FOXA1 R219S蛋白而不结合FOXA1 WT蛋白。其中,EMSA结果发现,咪唑烷基脲、氨磷汀和曲氟尿苷均能够竞争性抑制FOXA1 R219S蛋白与DNA的结合;CCK8结果发现,曲氟尿苷对前列腺癌细胞具有较强的杀伤效果(IC_(50)=15.4μmol/L)。综上所述,本研究初步筛选到FOXA1 R219S选择性靶向的药物,为晚期前列腺癌靶向药物的开发奠定了基础。 展开更多
关键词 FOXA1 r219s 虚拟筛选 sPr 前列腺癌 靶向治疗
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MAPT-isoform 0N3R is essential for human brain development:Loss-of-function for novel TAU-associated disease paradigms
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作者 Hans Zempel 《Neural Regeneration Research》 2026年第8期3349-3351,共3页
Hans Zempel1,2 TAU,a microtubule-associated protein,encoded by the microtubule-associated protein tau(MAPT)gene,is a central regulator of microtubule stability and axonal function in the human brain,with its pathologi... Hans Zempel1,2 TAU,a microtubule-associated protein,encoded by the microtubule-associated protein tau(MAPT)gene,is a central regulator of microtubule stability and axonal function in the human brain,with its pathological aggregation representing a hallmark of Alzheimer’s disease and related tauopathies.Despite extensive research into the role of TAU in neurodegeneration,its essentiality for human brain development has remained unclear.This perspective synthesizes recent genetic,molecular,and cellular evidence to demonstrate that the human brain-specific TAU isoform 0N3R is indispensable for proper neurodevelopment,pointing to loss-of-function of this isoform as a novel paradigm for TAU-associated disease.Alternative splicing of MAPT generates six brain-specific TAU isoforms,with 0N3R being exclusively expressed during fetal brain development.Analysis of large-scale human genetic datasets(gnomAD v4.0.0)reveals a high probability of loss-of-function intolerance(pLI=0.96)for the 0N3R isoform.This is in stark contrast to the canonical Matched Annotation from the NCBI and EMBL-EBI(MANE)transcript and peripheral“Big TAU,”both of which are tolerant to loss-of-function mutations.This intolerance is further supported by the scarcity of loss-of-function mutations in 0N3R-encoding exons and high missense constraint scores,suggesting strong evolutionary selection against disruption of this isoform.Functional studies using human induced pluripotent stem cell-derived cortical neurons with CRISPR-Cas9-mediated MAPT knockout reveal that,unlike in murine models where compensation by other microtubule-associated proteins occurs,loss of TAU in human neurons leads to deficits in neurite outgrowth,axon initial segment shortening,and a trend toward hyperexcitability,accompanied by broad transcriptomic changes affecting genes involved in microtubule organization and synaptic structure.Remarkably,re-expression of any of the six human brain-specific TAU isoforms rescues these phenotypes,underscoring their functional redundancy during development.These findings position the 0N3R isoform as essential for human brain development and suggest that loss-of-function mutations affecting this isoform likely result in neurodevelopmental impairment,potentially manifesting as intellectual disability without overt dysmorphic features.This contrasts with the apparent tolerance to MAPT loss-of-function in mice and peripheral tissues,highlighting a critical species-and isoform-specific requirement for TAU in human neurodevelopment.The hypothesis of 0N3R-TAU loss-of-function intolerance opens new avenues for understanding neurodevelopmental disorders and refines the conceptual framework of TAU-associated disease mechanisms beyond toxic gain-of-function. 展开更多
关键词 0N3r isoform alternative splicing Alzheimers disease intellectual disability neurodevelopmental disorders TAU protein TAUOPATHY
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Current and forecasted 10-year prevalence and incidence of inflammatory bowel disease in Hong Kong,Japan,and the United States
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作者 Yin Zhang Hsingwen Chung +7 位作者 Qi-Wen Fang You-Ran Xu Yong-Jing Zhang Ko Nakajo Ian Chi-Kei Wong Wai-Keung Leung Hong Qiu Xue Li 《World Journal of Gastroenterology》 2025年第18期32-51,共20页
BACKGROUND The rising incidence of inflammatory bowel disease(IBD)globally has increased disease burden and economic impact.Gaps remain in understanding the IBD burden between Asian and Western populations.AIM To esti... BACKGROUND The rising incidence of inflammatory bowel disease(IBD)globally has increased disease burden and economic impact.Gaps remain in understanding the IBD burden between Asian and Western populations.AIM To estimate the current and following 10-year prevalence and incidence of IBD in Hong Kong,Japan,and the United States.METHODS Patients diagnosed with IBD were identified from a territory-wide electronic medical records database in Hong Kong(2003-2022,including all ages)and two large employment-based healthcare claims databases in Japan and the United States(2010-2022,including<65 age).We used Autoregressive Integrated Moving Average models to predict prevalence and incidence from 2023 to 2032,stratified by disease subtype[ulcerative colitis(UC);Crohn’s disease(CD)],sex,and age,with 95%prediction intervals(PIs).The forecasted annual average percentage change(AAPC)with 95%confidence intervals was calculated.RESULTS The age-standardized prevalence of IBD for 2032 is forecasted at 105.88 per 100000 in Hong Kong(95%PI:83.01-128.75,AAPC:5.85%),645.79 in Japan(95%PI:562.51-741.39,AAPC:5.78%),and 629.85 in the United States(95%PI:569.09-690.63,AAPC:2.85%).Prevalence is estimated to rise most significantly among those under 18 in Japan and the United States.Over the next decade,the incidence of IBD is estimated to increase annually by 3.3%in Hong Kong with forecasted increases across all age groups(although the AAPC for each group is not statistically significant);by 2.88%in Japan with a significant rise in those under 18 and stability in 18-65;and remaining stable in the United States.By 2032,the prevalence of CD is estimated to surpass UC in Hong Kong and the United States,whereas UC will continue to be more prevalent in Japan.A higher prevalence and incidence of IBD is forecast for males in Hong Kong and Japan,whereas rates will be similar for both males and females in the United States.CONCLUSION The prevalence of IBD is forecasted to increase in Hong Kong,Japan,and the United States,while estimates of incidence vary.The forecasts show distinct patterns across disease subtype,sex,and age groups.Health systems will need to plan for the predicted increasing prevalence among different demographics. 展开更多
关键词 Inflammatory bowel disease Crohn’s disease Ulcerative colitis EPIDEMIOLOGY forecast modeling
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Verification of an operational ocean circulation-surface wave coupled forecasting system for the China's seas 被引量:5
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作者 WANG Guansuo ZHAO Chang +2 位作者 XU Jiangling QIAO Fangli XIA Changshui 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第2期19-28,共10页
An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation sin... An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation since November 1, 2007. In this paper we comprehensively present the simulation and verification of the system, whose distinguishing feature is that the wave-induced mixing is coupled in the circulation model. In particular, with nested technique the resolution in the China's seas has been updated to(1/24)° from the global model with(1/2)°resolution. Besides, daily remote sensing sea surface temperature(SST) data have been assimilated into the model to generate a hot restart field for OCFS-C. Moreover, inter-comparisons between forecasting and independent observational data are performed to evaluate the effectiveness of OCFS-C in upper-ocean quantities predictions, including SST, mixed layer depth(MLD) and subsurface temperature. Except in conventional statistical metrics, non-dimensional skill scores(SS) is also used to evaluate forecast skill. Observations from buoys and Argo profiles are used for lead time and real time validations, which give a large SS value(more than 0.90). Besides, prediction skill for the seasonal variation of SST is confirmed. Comparisons of subsurface temperatures with Argo profiles data indicate that OCFS-C has low skill in predicting subsurface temperatures between 100 m and 150 m. Nevertheless, inter-comparisons of MLD reveal that the MLD from model is shallower than that from Argo profiles by about 12 m, i.e., OCFS-C is successful and steady in MLD predictions. Validation of 1-d, 2-d and 3-d forecasting SST shows that our operational ocean circulation-surface wave coupled forecasting model has reasonable accuracy in the upper ocean. 展开更多
关键词 operational forecast sea surface temperature mixed layer depth lead time subsurface temperature ocean circulation-surface wave coupled forecast system China's seas
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Forecasting Inflation Rate of Zambia Using Holt’s Exponential Smoothing 被引量:2
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作者 Stanley Jere Mubita Siyanga 《Open Journal of Statistics》 2016年第2期363-372,共10页
In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2... In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2010 to May 2014. Results show that the ARIMA ((12), 1, 0) is an adequate model which best fits the CPI time series data and is therefore suitable for forecasting CPI and subsequently the inflation rate. However, the choice of the Holt’s exponential smoothing is as good as an ARIMA model considering the smaller deviations in the mean absolute percentage error and mean square error. Moreover, the Holt’s exponential smoothing model is less complicated since you do not require specialised software to implement it as is the case for ARIMA models. The forecasted inflation rate for April and May, 2015 is 7.0 and 6.6 respectively. 展开更多
关键词 INFLATION Holt’s Exponential smoothing forecasting Consumer Price Index Mean square Error and Mean Absolute Percentage Error
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Forecasting Short Time Series with Missing Data by Means of Energy Associated to Series 被引量:2
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作者 Cristian Rodríguez Rivero Julián Pucheta +2 位作者 Sergio Laboret Daniel Patino Víctor Sauchelli 《Applied Mathematics》 2015年第9期1611-1619,共9页
In this work an algorithm to predict short times series with missing data by means energy associated of series using artificial neural networks (ANN) is presented. In order to give the prediction one step ahead, a com... In this work an algorithm to predict short times series with missing data by means energy associated of series using artificial neural networks (ANN) is presented. In order to give the prediction one step ahead, a comparison between this and previous work that involves a similar approach to test short time series with uncertainties on their data, indicates that a linear smoothing is a well approximation in order to employ a method for uncompleted datasets. Moreover, in function of the long- or short-term stochastic dependence of the short time series considered, the training process modifies the number of patterns and iterations in the topology according to a heuristic law, where the Hurst parameter H is related with the short times series, of which they are considered as a path of the fractional Brownian motion. The results are evaluated on high roughness time series from solutions of the Mackey-Glass Equation (MG) and cumulative monthly historical rainfall data from San Agustin, Cordoba. A comparison with ANN nonlinear filters is shown in order to see a better performance of the outcomes when the information is taken from geographical point observation. 展开更多
关键词 Artificial Neural Networks rainfall forecasting Energy Associated to Time series Hurst’s Parameter
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Forecasting Oil Production in North Dakota Using the Seasonal Autoregressive Integrated Moving Average (S-ARIMA) 被引量:1
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作者 Jaesung Choi David C. Roberts EunSu Lee 《Natural Resources》 2015年第1期16-26,共11页
North Dakota’s oil production has been rapidly increasing during the past several years. The state’s oil production in March 2013 even increased to more than twice the quantity produced in March 2011, and the estima... North Dakota’s oil production has been rapidly increasing during the past several years. The state’s oil production in March 2013 even increased to more than twice the quantity produced in March 2011, and the estimated Bakken Formation reserves were reported very large compared with those of the United Arab Emirates. It eventually makes a question to us of how much oil will be able to be actually extracted with currently available technologies. To answer this question, this paper forecasts future oil development trend in North Dakota using the Seasonal Autoregressive Integrated Moving Average (S-ARIMA) model. Nonstationarity derived from a stochastic trend and the abrupt structural change of oil industry was a big potential problem, but through the Quandt Likelihood Ratio test, we found break points, which allowed us to select a model fitting period suitable for the S-ARIMA method to provide accurate statistical inference for the historical period. The seven major oil producing counties were investigated to determine whether the current oil boom was consistent across all oil fields in North Dakota. Empirical estimates show that North Dakota’s oil production will be more than double in the next five years. What we can predict with great certainty is that North Dakota’s influence over domestic and global oil supply systems will increase in the near future, especially over the next five to six years. This is good news for those who are concerned about domestic energy security in the USA. 展开更多
关键词 Bakken FOrMATION forecasting NOrTH Dakota OIL s-ArIMA
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Forecasting Diabetes Patients Attendance at Al-Baha Hospitals Using Autoregressive Fractional Integrated Moving Average (ARFIMA) Models
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作者 Salem Al Zahrani Fath Al Rahman Al Sameeh +1 位作者 Abdulaziz C. M. Musa Ashaikh A. A. Shokeralla 《Journal of Data Analysis and Information Processing》 2020年第3期183-194,共12页
Diabetes has become a concern in the developed and developing countries with its growing number of patients reported to the ministry of health records. This paper discusses the use of the Autoregressive Fractional Mov... Diabetes has become a concern in the developed and developing countries with its growing number of patients reported to the ministry of health records. This paper discusses the use of the Autoregressive Fractional Moving Average (ARFIMA) technique to modeling the diabetes patient’s attendance at Al-Baha hospitals using monthly time series data. The data used in the analysis of this paper are monthly readings of diabetes patients data covered the period January 2006-December 2016. The data were collected from the General Directorate of Health Affairs, Al-Baha region. The autoregressive fractional moving average approach was applied to the data through the model identification, estimation, diagnostic checking and forecasting. Hurst test results and ACF confirmed that there is a long memory behavior in diabetic patient’s data. Also, the fractional difference to diabetes series data revealed that (<em>d</em> = 0.44). Moreover, unit root tests indicated that the fractional difference of diabetes series level is stationary. Furthermore, according to AIC and BIC of model selection criteria ARFIMA (1, 0.44, 0) model shown the smallest values, hence this model was chosen as an adequate represents the data. Also, a diagnostic check confirmed that ARFIMA was appropriate and highly recommended in modeling and forecasting this type of data. 展开更多
关键词 Long Memory ArFIMA rescaled range r/s Method Diabetes Patients
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High-precision chaotic radial basis function neural network model:Data forecasting for the Earth electromagnetic signal before a strong earthquake
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作者 Guocheng Hao Juan Guo +2 位作者 Wei Zhang Yunliang Chen David AYuen 《Geoscience Frontiers》 SCIE CAS CSCD 2022年第1期364-373,共10页
The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and irregularities.The change tendency may be related to the occurrence of earthquake disasters... The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and irregularities.The change tendency may be related to the occurrence of earthquake disasters.Forecasting of the underlying intensity trend plays an important role in the analysis of data and disaster monitoring.Combining chaos theory and the radial basis function neural network,this paper proposes a forecasting model of the chaotic radial basis function neural network to conduct underlying intensity trend forecasting by the Earth’s natural pulse electromagnetic field signal.The main strategy of this forecasting model is to obtain parameters as the basis for optimizing the radial basis function neural network and to forecast the reconstructed Earth’s natural pulse electromagnetic field data.In verification experiments,we employ the 3 and 6 days’data of two channels as training samples to forecast the 14 and 21-day Earth’s natural pulse electromagnetic field data respectively.According to the forecasting results and absolute error results,the chaotic radial basis function forecasting model can fit the fluctuation trend of the actual signal strength,effectively reduce the forecasting error compared with the traditional radial basis function model.Hence,this network may be useful for studying the characteristics of the Earth’s natural pulse electromagnetic field signal before a strong earthquake and we hope it can contribute to the electromagnetic anomaly monitoring before the earthquake. 展开更多
关键词 Earth’s natural pulse electromagnetic field Chaos theory radial Basis Function neural network forecasting model
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Forecasting Alzheimer’s Disease Using Combination Model Based on Machine Learning
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作者 He Li Yuhang Wu +2 位作者 Yingnan Zhang Tao Wei Yufeng Gui 《Applied Mathematics》 2018年第4期403-417,共15页
As the acceleration of aged population tendency, building models to forecast Alzheimer’s Disease (AD) is essential. In this article, we surveyed 1157 interviewees. By analyzing the results using three machine learnin... As the acceleration of aged population tendency, building models to forecast Alzheimer’s Disease (AD) is essential. In this article, we surveyed 1157 interviewees. By analyzing the results using three machine learning methods—BP neural network, SVM and random forest, we can derive the accuracy of them in forecasting AD, so that we can compare the methods in solving AD prediction. Among them, random forest is the most accurate method. Moreover, to combine the advantages of the methods, we build a new combination forecasting model based on the three machine learning models, which is proved more accurate than the models singly. At last, we give the conclusion of the connection between life style and AD, and provide several suggestions for elderly people to help them prevent AD. 展开更多
关键词 Alzheimers Disease BP NEUrAL Network sVM rANDOM FOrEsT Combination forecasting Model
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The forecasting efficiency under different selected regions by Pattern Informatics Method and seismic potential estimation in the North-South Seismic Zone
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作者 Weixi Tian Yongxian Zhang 《Earthquake Science》 2024年第4期368-382,共15页
In 2022,four earthquakes with M_(S)≥6.0 including the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes occurred in the North-South Seismic Zone(NSSZ),which demonstrated high and strong seismicity.Pattern Informatics(... In 2022,four earthquakes with M_(S)≥6.0 including the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes occurred in the North-South Seismic Zone(NSSZ),which demonstrated high and strong seismicity.Pattern Informatics(PI)method,as an effective long and medium term earthquake forecasting method,has been applied to the strong earthquake forecasting in Chinese mainland and results have shown the positive performance.The earthquake catalog with magnitude above M_(S)3.0 since 1970 provided by China Earthquake Networks Center was employed in this study and the Receiver Operating Characteristic(ROC)method was applied to test the forecasting efficiency of the PI method in each selected region related to the North-South Seismic Zone systematically.Based on this,we selected the area with the best ROC testing result and analyzed the evolution process of the PI hotspot map reflecting the small seismic activity pattern prior to the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes.A“forward”forecast for the area was carried out to assess seismic risk.The study shows the following.1)PI forecasting has higher forecasting efficiency in the selected study region where the difference of seismicity in any place of the region is smaller.2)In areas with smaller differences of seismicity,the activity pattern of small earthquakes prior to the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes can be obtained by analyzing the spatio-temporal evolution process of the PI hotspot map.3)The hotspot evolution in and around the southern Tazang fault in the study area is similar to that prior to the strong earthquakes,which suggests the possible seismic hazard in the future.This study could provide some ideas to the seismic hazard assessment in other regions with high seismicity,such as Japan,Californi,Turkey,and Indonesia. 展开更多
关键词 Luding M_(s)6.8 and Menyuan M_(s)6.9 earthquake Pattern Informatics Method North-south seismic Zone earthquake forecasting seismic activity pattern.
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Forecasting the New Trends about the Consumer Behavior in the Cruise Industry Post COVID-19
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作者 Ana Lucia Rodrigues da Silva Reinaldo Castro Souza 《Journal of Data Analysis and Information Processing》 2022年第1期58-77,共20页
This paper presented the new sanitary and health protocols implemented by cruise companies in order to internationally resuming the industry. The perception of Brazilians regarding these new protocols was identified t... This paper presented the new sanitary and health protocols implemented by cruise companies in order to internationally resuming the industry. The perception of Brazilians regarding these new protocols was identified through a quantitative survey with a sample of 412 Brazilian respondents, carried out between May and June 2021. As main results, sanitary and health protocols that do not affect their experiences on board were identified, as well as those protocols that compromised the experience perceived by the future traveler. The respondents’ propensity to travel on cruise ships and their perceptions about the influence of the ship size, the number of ports of call, nationalities on board, the number of vips, among other aspects, were also analyzed. Finally, in the final section of this paper, we presented an estimation of the expected number of cruisers for the 21/22 cruising season in Brazil, based on a kind Bayesian argument, considering different scenarios for the forthcoming season. 展开更多
关键词 Cruise Industry COVID-19 sanitary and Health Protocols Quantitative sur-vey forecasting Brazilian’s Cruisers
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Estimation and Forecasting Survival of Diabetic CABG Patients (Kalman Filter Smoothing Approach)
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作者 M. Saleem K. H. Khan Nusrat Yasmin 《American Journal of Computational Mathematics》 2015年第4期405-413,共9页
In this paper, we present a new approach (Kalman Filter Smoothing) to estimate and forecast survival of Diabetic and Non Diabetic Coronary Artery Bypass Graft Surgery (CABG) patients. Survival proportions of the patie... In this paper, we present a new approach (Kalman Filter Smoothing) to estimate and forecast survival of Diabetic and Non Diabetic Coronary Artery Bypass Graft Surgery (CABG) patients. Survival proportions of the patients are obtained from a lifetime representing parametric model (Weibull distribution with Kalman Filter approach). Moreover, an approach of complete population (CP) from its incomplete population (IP) of the patients with 12 years observations/follow-up is used for their survival analysis [1]. The survival proportions of the CP obtained from Kaplan Meier method are used as observed values yt?at time t (input) for Kalman Filter Smoothing process to update time varying parameters. In case of CP, the term representing censored observations may be dropped from likelihood function of the distribution. Maximum likelihood method, in-conjunction with Davidon-Fletcher-Powell (DFP) optimization method [2] and Cubic Interpolation method is used in estimation of the survivor’s proportions. The estimated and forecasted survival proportions of CP of the Diabetic and Non Diabetic CABG patients from the Kalman Filter Smoothing approach are presented in terms of statistics, survival curves, discussion and conclusion. 展开更多
关键词 CABG PATIENTs Complete and Incomplete Populations Weibull & Distribution Kalman Filter Maximum Likelihood METHOD DFP METHOD EsTIMATION and forecasting of survivors PrOPOrTIONs
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About A New Complex Method of Climates Reconstruction and Forecasting of Climate Changes in the Future
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作者 Valentina V. Ukraintseva 《Journal of Earth Science and Engineering》 2015年第2期122-129,共8页
This paper deals with a new integrated method of reconstruction and forecasting of climatic changes in future. The method is based on proxy data pollen-spore analysis method, 14C analysis method, nowadays meteorologic... This paper deals with a new integrated method of reconstruction and forecasting of climatic changes in future. The method is based on proxy data pollen-spore analysis method, 14C analysis method, nowadays meteorological data, and data about of solar activity expressed in numbers of W (Wolf). Here we present the results of investigation of sediments of the 2nd Fomich River terrace, Taymyr Peninsula, Russia. The formation of the peat bog started 10500 ± 140 years BP and continued during the entire Holocene. The pollen analysis of the sediment samples of the 2nd Fomich River terrace and the analysis of surface samples from a larch forest, typical of this region, reveals two phytochrones: both climatically preconditioned--tundra phytochrone (I1-4) and forest phytochrone (Ⅱ1-4). The techniques of reconstruction and forecasting of basic elements of climate are presented and discussed in details. 展开更多
关键词 Holocene pollen analysis 14C analysis fossil and recent pollen-spore spectra (pollen-spore spectra) sI similarityindex) basic elements of climate solar activity Wolf's number (W) forecasting of climate changes.
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