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Seismic effectiveness evaluation and optimized design of tie up method for securing museum collections
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作者 Wang Meng Yan Yi +3 位作者 Yang Weiguo Liu Pei Ge Jiaqi Ma Botao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第3期741-763,共23页
To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used ... To quantify the seismic effectiveness of the most commonly used fishing line tie up method for securing museum collections and optimize fixed strategies for exhibitions,shaking table tests of the seismic systems used for typical museum collection replicas have been carried out.The influence of body shape and fixed measure parameters on the seismic responses of replicas and the interaction behavior between replicas and fixed measures have been explored.Based on the results,seismic effectiveness evaluation indexes of the tie up method are proposed.Reasonable suggestions for fixed strategies are given,which provide a basis for the exhibition of delicate museum collections considering the principle of minimizing seismic responses and intervention.The analysis results show that a larger ratio of height of mass center to bottom diameter led to more intense rocking responses.Increasing the initial pretension of fishing lines was conducive to reducing the seismic responses and stress variation of the lines.Through comprehensive consideration of the interaction forces and effective securement,it is recommended to apply 20%of breaking stress as the initial pretension.For specific museum collections that cannot be effectively protected by the independent tie up method,an optimized strategy of a combination of fishing lines and fasteners is recommended. 展开更多
关键词 tie up method museum collections shaking table test seismic effectiveness optimized design
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Analysis on Effectiveness of Testing and Evaluation of Bridge Repair and Reinforcement
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作者 Huigeng Liu Ke Wu 《Journal of Architectural Research and Development》 2023年第2期11-14,共4页
Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering... Bridge engineering is an important part of basic engineering in today’s transportation field,and its quality and performance have a vital impact on the improvement and development of modern transportation engineering.With the continuous development of transportation engineering,the maintenance and reinforcement of existing bridges are also being given more emphasis.In order to scientifically evaluate the effectiveness of bridge maintenance and reinforcement,this paper analyzes its detection and evaluation,including the significance,key points,and main methods of detection and evaluation.Therefore,this analysis aim to provide some reference for the maintenance and reinforcement and the quality improvement of bridge engineering. 展开更多
关键词 Bridge engineering Maintenance and reinforcement testing and evaluation method
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Analysis of the integrated test and evaluation methods of tidal current energy generating devices in the offshore testing site
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作者 郭文瑞 朱永强 +3 位作者 叶青 李雪临 王鑫 段春明 《Marine Science Bulletin》 CAS 2014年第2期60-71,共12页
Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformat... Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformation and marine renewable energy development. By analyzing three core indicators, including the power output characteristics of the tidal current device, the generating capacity, energy conversion efficiency, proposed the test contents and evaluation methods of indicators are proposed in this paper; and based on the research of wind farms, power quality testing and assessment methods of offshore tidal energy device are proposed; given the security access to the test contents of tidal current energy device, tidal current energy device running conditions in the testing ground are comprehensively assessed. 展开更多
关键词 testing ground tidal current energy generating device integrated test evaluation method
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Prevention and Control Effects of New Biological Formulations Sprayed by Different Methods on Proceras venosatus (Walker) and Tryporyza intacta Snellen in Middle and Late Stages
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作者 Li Wenfeng Shan Hongli +6 位作者 Wang Xiaoyan Zhang Rongyue Luo Zhiming Fang Chao Mao Yonglei Yin Jiong Huang Yingkun 《Plant Diseases and Pests》 CAS 2018年第3期29-32,共4页
To screen new biological formulations, accurate and efficient application technology, field test was conducted with 72% Bacillus thuringiensis(Bt)·monosultap WP, 8% lambda-cyhalothrin·emamectin benzoate SA a... To screen new biological formulations, accurate and efficient application technology, field test was conducted with 72% Bacillus thuringiensis(Bt)·monosultap WP, 8% lambda-cyhalothrin·emamectin benzoate SA and 3.6% lambda-cyhalothrin·Bt SA through manual spraying and unmanned aerial vehicle spraying. Test results and comprehensive evaluation analysis demonstrated that 72% Bt·monosultap WP and 8%lambda-cyhalothrin·emamectin benzoate SA by manual spraying and unmanned aerial vehicle spraying had good prevention and control effect on strains and internodes damaged by Tryporyza intacta Snellen in middle and late stage, which were ideal new biological formulations with high effi-ciency and low risk for prevention and control of T. intacta in middle and late stage, and could be popularized in sugarcane area. 72% Bt·monosultap WP at the dose of 3 000 g/hectare and 8% lambda-cyhalothrin·emamectin benzoate SA at the dose of 750 mL/hectare could be sprayed in mid September at the peak occurrence period of the forth and fifth generations of T. intacta and Proceras venosatus. Agents were diluted with 900 kg water per hectare, and manually sprayed with electric knapsack sprayer; or agents were diluted with 15 kg of Haoyang aerial control special addi-tives and water per hectare, and sprayed with unmanned aerial vehicle. The control effect against borer-damaged strain rate was above 81.3% and that against borer-damaged internode rate was above 88.6%. 展开更多
关键词 Biological formulation Different spraying methods Proceras venosatus (Walker) and Tryporyza intacta Snellen in middle and late stage Control effect evaluation
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Modeling and Experimental Analysis of Roughness Effect on Ultrasonic Nondestructive Evaluation of Micro-crack 被引量:2
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作者 Zhe Wang Zhichao Fan +3 位作者 Xuedong Chen Yihua Kang Jingwei Cheng Wei Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第6期126-137,共12页
A high-precision evaluation of ultrasonic detection sensitivity for a micro-crack can be restricted by a corroded rough surface when the surface microtopography is of the same order of magnitude as the crack depth.In ... A high-precision evaluation of ultrasonic detection sensitivity for a micro-crack can be restricted by a corroded rough surface when the surface microtopography is of the same order of magnitude as the crack depth.In this study,a back-surface micro-crack is considered as a research target.A roughness-modified ultrasonic testing model for micro-cracks is established based on a multi-Gaussian beam model and the principle of phase-screen approximation.The echo signals of micro-cracks and noises corresponding to different rough front surfaces and rough back surfaces are obtained based on a reference reflector signal acquired from a two-dimensional simulation model.Further compari-son between the analytical and numerical models shows that the responses of micro-cracks under the effects of dif-ferent corroded rough surfaces can be accurately predicted.The numerical and analytical results show that the echo signal amplitude of the micro-crack decreases significantly with an increase in roughness,whereas the noise ampli-tude slightly increases.Moreover,the effect of the rough front surface on the echo signal of the micro-crack is greater than that of the rough back surface.When the root-mean-square(RMS)height of the surface microtopography is less than 15μm,the two rough surfaces have less influence on the echo signals detected by a focused transducer with a frequency of 5 MHz and diameter of 6 mm.A method for predicting and evaluating the detection accuracy of micro-cracks under different rough surfaces is proposed by combining the theoretical model and a finite element simulation.Then,a series of rough surface samples containing different micro-cracks are fabricated to experimentally validate the evaluation method. 展开更多
关键词 Surface roughness MICRO-CRACK Ultrasonic testing model Detection accuracy evaluation method
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The single-event effect evaluation technology for nano integrated circuits 被引量:1
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作者 郑宏超 赵元富 +4 位作者 岳素格 范隆 杜守刚 陈茂鑫 于春青 《Journal of Semiconductors》 EI CAS CSCD 2015年第11期75-79,共5页
Single-event effects of nano scale integrated circuits are investigated. Evaluation methods for singleevent transients, single-event upsets, and single-event functional interrupts in nano circuits are summarized and c... Single-event effects of nano scale integrated circuits are investigated. Evaluation methods for singleevent transients, single-event upsets, and single-event functional interrupts in nano circuits are summarized and classified in detail. The difficulties in SEE testing are discussed as well as the development direction of test technology, with emphasis placed on the experimental evaluation of a nano circuit under heavy ion, proton, and laser irradiation. The conclusions in this paper are based on many years of testing at accelerator facilities and our present understanding of the mechanisms for SEEs, which have been well verified experimentally. 展开更多
关键词 single-event effect heavy ion test radiation evaluation method
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Evaluation on washback effects of College English Test Band 4 被引量:1
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作者 WANG Wen-jun 《Sino-US English Teaching》 2010年第2期35-40,共6页
The paper is an evaluative research on the possible washback effects of College English Test. By comparing and analyzing the differences between the old and new tests, it points out three major changes and their possi... The paper is an evaluative research on the possible washback effects of College English Test. By comparing and analyzing the differences between the old and new tests, it points out three major changes and their possible washback effects on the process of English language teaching and learning: abandon the part of Grammar & Vocabulary, increase the proportion of listening test and change the test reporting form. 展开更多
关键词 washback effects test evaluation College English Test
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Scale Effects and a Method for Similarity Evaluation in Micro Electrical Discharge Machining
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作者 LIU Qingyu ZHANG Qinhe +3 位作者 WANG Kan ZHU Guang FU Xiuzhuo ZHANG Jianhua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第6期1193-1199,共7页
Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at th... Electrical discharge machining(EDM) is a promising non-traditional micro machining technology that offers a vast array of applications in the manufacturing industry. However, scale effects occur when machining at the micro-scale, which can make it difficult to predict and optimize the machining performances of micro EDM. A new concept of "scale effects" in micro EDM is proposed, the scale effects can reveal the difference in machining performances between micro EDM and conventional macro EDM. Similarity theory is presented to evaluate the scale effects in micro EDM. Single factor experiments are conducted and the experimental results are analyzed by discussing the similarity difference and similarity precision. The results show that the output results of scale effects in micro EDM do not change linearly with discharge parameters. The values of similarity precision of machining time significantly increase when scaling-down the capacitance or open-circuit voltage. It is indicated that the lower the scale of the discharge parameter, the greater the deviation of non-geometrical similarity degree over geometrical similarity degree, which means that the micro EDM system with lower discharge energy experiences more scale effects. The largest similarity difference is 5.34 while the largest similarity precision can be as high as 114.03. It is suggested that the similarity precision is more effective in reflecting the scale effects and their fluctuation than similarity difference. Consequently, similarity theory is suitable for evaluating the scale effects in micro EDM. This proposed research offers engineering values for optimizing the machining parameters and improving the machining performances of micro EDM. 展开更多
关键词 Electrical Discharge Machining (EDM) micro EDM Scale effect Similarity theory Similarity evaluating method
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Method of effective evaluation for examination of chloride ion in concrete
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作者 SUNGWen-pei CHENKuen-suan LINHsue-chun 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第3期159-165,共7页
The chloride ion contained in reinforced concrete seriously corrodes the steel surface and damages concrete, resulting in inferior reinforced concrete that strength seriously compromises the entire structure’s safety... The chloride ion contained in reinforced concrete seriously corrodes the steel surface and damages concrete, resulting in inferior reinforced concrete that strength seriously compromises the entire structure’s safety. Consequently, the examination of chloride ions contained in reinforced concrete becomes an important part of a complete quality control procedure. To effectively check the concentration of chloride ions in concrete, the evaluation process should be accurate and precise. Laboratory data ob- tained using existing evaluation methods for the examination of chloride ion are not sufficiently objective to yield reliable results with accuracy and consistency for each sample. An evaluation algorithm with capability to define indices of precision degree (Ep) and accuracy degree (Ea) is presented in this paper. The authors established a statistically reliable index of unbiased estimators and equations to critically examine the laboratory methods’ precision, accuracy degrees and application value for measuring chlorine ion concentration in reinforced concrete. 展开更多
关键词 Concrete quality control Multi-laboratory Test error Accuracy degree Precision degree Natural estimator Acceptance testing Examination methods evaluation criteria
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A Study on the Evaluation Method and Evaluation Model of the Effectiveness of Consumer Financial Education
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作者 FANG Yun CHEN ying Yerzhigit Khalikova 《International English Education Research》 2017年第2期25-28,共4页
With the understanding of the importance of financial education and research, the study of the effectiveness of financial education is more and more, but there have been debate on the effectiveness of financial educat... With the understanding of the importance of financial education and research, the study of the effectiveness of financial education is more and more, but there have been debate on the effectiveness of financial education and education costs. This paper summarizes and classifies the methods and models to improve the effective research of financial education, including improving the effectiveness of financial education and improving the effectiveness of financial education through the design of different educational methods. The guiding principles of the evaluation of the effectiveness of financial consumer education proposed by the International Financial Consumers' Education Network (INFE) and the guidance of our government on the evaluation of the effectiveness of financial education. 展开更多
关键词 Consumer The effectiveness of Financial Education evaluation Method evaluation Model
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Study on Evaluation Method of Failure Pressure for Pipeline with Axially Adjacent Defects
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作者 SUN Ming-ming FANG Hong-yuan +2 位作者 DU Xue-ming WANG Wen-hua LI Xin 《China Ocean Engineering》 SCIE EI CSCD 2023年第4期598-612,共15页
The interaction between axially adjacent defects is more significant than that between circumferentially aligned defects.However,the existing failure pressure assessment methods cannot accurately predict the failure p... The interaction between axially adjacent defects is more significant than that between circumferentially aligned defects.However,the existing failure pressure assessment methods cannot accurately predict the failure pressure of axial adjacent defects.In the paper,the finite element model is adopted to analyze the influence of defect size,distribution mode and spacing between adjacent defects on failure pressure.A new failure pressure evaluation method is proposed by establishing the effective depth calculation model of corrosion colony with different distribution model.The burst test of X52 pipeline is carried out to verify the applicability of the method.It shows that the results of new method are consistent with the test results of pipeline with various defects and steel grades. 展开更多
关键词 steel pipeline effective depth axially adjacent defects burst test evaluation method
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Evaluation of a Plasma hCG Method for Point of Care Testing with the Aim of Shortening Test-Turnaround-Times
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作者 Anna-Karin Wikstrom Magnus Hagmar +1 位作者 Goran Ronquist Anders Larsson 《Open Journal of Obstetrics and Gynecology》 2015年第6期341-343,共3页
Objective: To examine the correlation between plasma hCG results obtained with the new i-STAT&reg hCG point of care test with those concomitantly obtained from the central hospital laboratory utilizing the same pa... Objective: To examine the correlation between plasma hCG results obtained with the new i-STAT&reg hCG point of care test with those concomitantly obtained from the central hospital laboratory utilizing the same patient samples. Methods: Prospective cross-sectional laboratory test evaluation. We compared plasma hCG results obtained with the i-STAT&reg hCG test (Abbott Point of Care, Princeton, NJ, USA) with Architect Ci8200 (Abbott Laboratories, Abbott Park, IL, USA). We also calculated the total coefficient of variation (CV) for the i-STAT&reg method. Results: The two methods showed a good linear correlation (R2 = 0.994;slope 1.03) and CV for the i-STAT&reg method was 2.1% - 5.2%. Conclusion: We suggest that the i-STAT&reg hCG blood assay could be used as a complement to urine hCG assays in clinical situations when rapid test results are needed and urine is not available. 展开更多
关键词 Human Chorionic Gonadotropin PREGNANCY Method evaluation Point of Care Test
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Employment Quality EvaluationModel Based on Hybrid Intelligent Algorithm
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作者 Xianhui Gu Xiaokan Wang Shuang Liang 《Computers, Materials & Continua》 SCIE EI 2023年第1期131-139,共9页
In order to solve the defect of large error in current employment quality evaluation,an employment quality evaluation model based on grey correlation degree method and fuzzy C-means(FCM)is proposed.Firstly,it analyzes... In order to solve the defect of large error in current employment quality evaluation,an employment quality evaluation model based on grey correlation degree method and fuzzy C-means(FCM)is proposed.Firstly,it analyzes the related research work of employment quality evaluation,establishes the employment quality evaluation index system,collects the index data,and normalizes the index data;Then,the weight value of employment quality evaluation index is determined by Grey relational analysis method,and some unimportant indexes are removed;Finally,the employment quality evaluation model is established by using fuzzy cluster analysis algorithm,and compared with other employment quality evaluation models.The test results show that the employment quality evaluation accuracy of the design model exceeds 93%,the employment quality evaluation error can meet the requirements of practical application,and the employment quality evaluation effect is much better than the comparison model.The comparison test verifies the superiority of the model. 展开更多
关键词 Employment quality fuzzy c-means clustering algorithm grey correlation analysis method evaluation model index system comparative test
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基于阵列声波测井的井下多尺度压裂效果评价方法 被引量:2
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作者 李宁 刘鹏 +2 位作者 范华军 胡江涛 武宏亮 《石油钻探技术》 CAS CSCD 北大核心 2024年第1期1-7,共7页
为有效监测水力压裂效果、提高储层压裂效果评价精度,基于阵列声波测井资料的井下压裂效果评价方法,采用反射斯通利波提取和成像技术定量表征近井筒压裂缝,建立适用于测井观测系统的叠前深度偏移成像算法,以实现远井压裂缝的高精度成像... 为有效监测水力压裂效果、提高储层压裂效果评价精度,基于阵列声波测井资料的井下压裂效果评价方法,采用反射斯通利波提取和成像技术定量表征近井筒压裂缝,建立适用于测井观测系统的叠前深度偏移成像算法,以实现远井压裂缝的高精度成像,形成了基于阵列声波测井的井下多尺度压裂效果评价方法,并在中国西部某油田X1水平井成功应用。研究表明,基于阵列声波测井资料评价的压裂缝发育程度与压裂液注入量呈正相关关系,并且压裂缝最为发育层段与地震蚂蚁体属性图中天然裂缝发育位置一致。基于阵列声波测井的井下压裂效果评价方法的提出,对表征井周数十米范围内不同尺度压裂缝的发育情况具有重要意义,对更好地发挥水力压裂技术对能源勘探开发行业的支撑作用具有一定指导意义。 展开更多
关键词 多尺度压裂 水力压裂 压裂效果 评价方法 声波测井 斯通利波
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新疆某健康体检机构重要异常结果分析与随访结果研究 被引量:1
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作者 韩雷 渠林楠 +2 位作者 江艳 伊力达尔·阿布迪外力 席晓玲 《现代医院》 2024年第1期99-101,106,共4页
目的研究新疆某健康体检机构重要异常结果人群分布特征及随访结果。方法选取2022年在新疆医科大学健康管理中心参加健康体检的受检者65045例,检出4665例有重要异常结果的受检者,制定重要异常结果A类B类随访规则,进行电话通知及1月、6月... 目的研究新疆某健康体检机构重要异常结果人群分布特征及随访结果。方法选取2022年在新疆医科大学健康管理中心参加健康体检的受检者65045例,检出4665例有重要异常结果的受检者,制定重要异常结果A类B类随访规则,进行电话通知及1月、6月随访,使用随访信息系统进行提醒及表单记录。结果4665例重要异常结果受检者中A类重要异常结果447例(9.58%),B类4218例(90.42%);男性2815例(60.34%)、女性1850例(39.66%),男性高于女性(P<0.05);年龄与重要异常结果存在相关性(P<0.05);41~50岁(1114例)、51~60岁(1211例)这两个年龄段重要段异常结果人数占比高。有效通知4457例(95.54%),通知后有效随访4397例(98.65%),失访60例(1.35%);电话随访后就诊2118例(48.17%),未就诊2279例(51.83%);未就诊男性1562(58.57%)高于女性717(41.45%),性别与是否就诊有统计学意义(P<0.05)。就诊后非肿瘤性疾病1194例(56.40%),恶性肿瘤性疾病97例(4.5%),未明确827例(39.1%)。结论重要异常结果男性高于女性,随年龄增长重要异常结果发生率增高。随访路径实施中通知及随访成功率还应提高。受检者对重要异常结果指标理解不够及重视程度不高(60.44%),未按随访建议进行及时就诊,需加强健康宣教提高其健康意识,督促其重视及时治疗,对提高疾病“早筛查,早评估,早干预”有重要意义。 展开更多
关键词 重要异常结果 健康体检 检后随访 效果评价
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恒压下GIS固体绝缘界面气隙缺陷放电严重程度评估 被引量:2
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作者 唐志国 李阳 《高压电器》 CAS CSCD 北大核心 2024年第2期62-68,77,共8页
为了研究GIS绝缘子界面气隙缺陷的放电发展过程,文中设计了空洞气隙缺陷模型,搭建了一套GIS气隙缺陷放电长期测试平台。基于缺陷模型的击穿电压对带有缺陷的试品施加90%Ub、60%Ub、30%Ub的交流恒压,使用UHF检测系统采集放电数据直至试... 为了研究GIS绝缘子界面气隙缺陷的放电发展过程,文中设计了空洞气隙缺陷模型,搭建了一套GIS气隙缺陷放电长期测试平台。基于缺陷模型的击穿电压对带有缺陷的试品施加90%Ub、60%Ub、30%Ub的交流恒压,使用UHF检测系统采集放电数据直至试品击穿。提取放电次数、放电幅值、放电时间间隔分析放电状态特征,发现GIS气隙缺陷放电发展过程存在两个阶段,前期放电幅值缓慢增大,放电脉冲逐渐稀疏,放电发展较为平稳;后期放电幅值急剧减小,放电脉冲密集,放电发展剧烈,采用k⁃means聚类算法及BP神经网络建立了气隙缺陷局放发展阶段的划分规则。研究表明,放电次数、放电幅值、放电时间间隔3种统计参量呈现阶段式单调性的趋势,可以用3种统计参量前向差分绝对值作为特征参量来评估GIS气隙放电严重程度;对GIS恒压试验进行聚类分析将放电过程划分为平稳劣化阶段和加速劣化阶段,随着外施电压水平的降低,平稳劣化阶段被压缩,加速劣化阶段占比升高。 展开更多
关键词 GIS绝缘子 气隙放电 恒压法 状态划分 评估
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长程居家多导睡眠监测评估发作性睡病日间嗜睡的应用价值
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作者 杨静 贾丽景 +4 位作者 毛卓锋 李鑫 李建华 杜风萍 李震中 《河北医药》 CAS 2024年第11期1686-1689,共4页
目的探讨一种可以定量评估发作性睡病日间嗜睡严重程度的监测方法并验证其效果。方法收集2021至2022年在河北医科大学第二医院神经内科确诊的发作性睡病患者相关信息,整理患者记录的睡眠日志,所有患者均采用便携式多导睡眠记录仪进行长... 目的探讨一种可以定量评估发作性睡病日间嗜睡严重程度的监测方法并验证其效果。方法收集2021至2022年在河北医科大学第二医院神经内科确诊的发作性睡病患者相关信息,整理患者记录的睡眠日志,所有患者均采用便携式多导睡眠记录仪进行长程居家多导睡眠监测,记录睡眠发作次数、发作时间及发作时长。结果发作性睡病患者三项睡眠量表评估分数均明显高于健康对照者,差异有统计学意义(P<0.05)。多导睡眠监测数据结果与睡眠日志在发作次数、发作时长方面结果一致。用药前后、停药后多导睡眠监测记录的发作次数均多于睡眠日志记录,多导睡眠监测记录的发作时长长于睡眠日志记录。结论长程居家多导睡眠监测可作为定量评估发作性睡病日间嗜睡的方法,评估发作性睡病病情严重程度及药物治疗的效果,提供更加客观的睡眠数据。 展开更多
关键词 发作性睡病 日间嗜睡 多导睡眠监测 评估方式 效果
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基于装置运行平稳性的石油化工安全管理策略研究 被引量:1
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作者 姜国刚 王海超 黄文萍 《石油炼制与化工》 CAS CSCD 北大核心 2024年第4期40-46,共7页
为了找出并评价石化装置支配性风险因素,实现安全生产风险源头控制和管理,满足石化装置安全生产风险控制的高效性要求,通过建立石化装置事故风险影响模型,运用决策试验与评估实验室方法(DEMATEL)从“现代事故因果连锁理论”视角分析发... 为了找出并评价石化装置支配性风险因素,实现安全生产风险源头控制和管理,满足石化装置安全生产风险控制的高效性要求,通过建立石化装置事故风险影响模型,运用决策试验与评估实验室方法(DEMATEL)从“现代事故因果连锁理论”视角分析发现人、机(物)等风险因素都受管理因素支配。进而,基于工艺稳定性、工艺稳定性修正、非计划停工3个指标建立石化装置平稳性模型,对装置运行平稳率进行追踪统计,并通过实例对该模型进行了分析和验证。结果表明:该石化装置运行平稳性模型可以量化追踪事故风险支配性因素的控制效果,可展示石化装置不同阶段下的风险特点,可作为装置事故风险预警指标和安全管理绩效指标,可提高装置的安全管理水平。 展开更多
关键词 DEMATEL 支配性事故风险 石化装置 安全管理 装置平稳性
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机器学习在人工增雨效果统计检验中的应用
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作者 李丹 林文 +3 位作者 刘群 冯宏芳 胡淑萍 汪智海 《应用气象学报》 CSCD 北大核心 2024年第1期118-128,共11页
利用福建省古田人工增雨试验基地2014年1月—2023年1月小时自然降水数据,结合线性拟合、多项式回归和样条回归等多种数学统计方法,开展决策树、支持向量机(SVM)和卷积神经网络(CNN)3种机器学习方法在估测目标区自然降水中的应用研究。... 利用福建省古田人工增雨试验基地2014年1月—2023年1月小时自然降水数据,结合线性拟合、多项式回归和样条回归等多种数学统计方法,开展决策树、支持向量机(SVM)和卷积神经网络(CNN)3种机器学习方法在估测目标区自然降水中的应用研究。目标区和对比区自然雨量关系模型对比结果表明:以区域平均面雨量为统计变量时,CNN和四项式回归效果相对较好,其中CNN的确定系数为0.516,均方根误差为1.097 mm;对平均面雨量进行六次方根变换后,各模型的精准度大幅提升,CNN表现最优,确定系数为0.658,其次为SVM;为克服目标区和对比区雨量时间序列效应及空间分布不均等问题,以面雨量空间格点数据作为研究对象,采用CNN 3种优化器(自适应矩估计、均方根传递和梯度随机下降)算法进行对比,发现基于自适应矩估计优化器建立目标区和对比区雨量关系模型最优,其降水估测值与实测值更接近,均方根误差最小,为0.61 mm。因此,利用CNN方法能够进一步优化目标区和对比区雨量关系模型,可为定量评估人工增雨效果提供参考。 展开更多
关键词 人工增雨效果评估 区域历史回归 机器学习 统计检验
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基于FAST和Sobol指数法的雷达系统效能敏感性分析
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作者 胡涛 申立群 +2 位作者 朱镜达 孙成会 董伟锋 《系统工程与电子技术》 EI CSCD 北大核心 2024年第2期561-569,共9页
为了以较小的代价快速提升对空探测雷达系统的综合效能,首先搭建了对空探测雷达系统综合效能的评估指标体系,在此基础上完成了综合效能评估模型的建立。选择两种基于方差原理的全局敏感性分析方法,即傅里叶幅度敏感性测试(Fourier ampli... 为了以较小的代价快速提升对空探测雷达系统的综合效能,首先搭建了对空探测雷达系统综合效能的评估指标体系,在此基础上完成了综合效能评估模型的建立。选择两种基于方差原理的全局敏感性分析方法,即傅里叶幅度敏感性测试(Fourier amplitudes sensitivity test,FAST)和Sobol指数法,分别从频域和时域对建立的评估模型进行敏感性分析。在基于FAST进行敏感性分析时,提出了21维输入指标所对应的特征频率集的选取方法;在基于Sobol指数法进行敏感性分析时,考虑了二阶及高阶敏感性指数的影响。对比FAST和Sobol指数法的分析结果,两种方法获得的敏感性分析结果具有较好的一致性。其中,功率和频率为对空探测雷达系统的主要影响指标,为雷达系统的研发和升级提供了可靠性依据。 展开更多
关键词 雷达系统 效能评估 敏感性分析 傅里叶幅度敏感性测试 Sobol指数法
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