期刊文献+
共找到19篇文章
< 1 >
每页显示 20 50 100
膈肌偏移与老年慢阻肺患者肺低衰减区比例及肺功能的相关性研究 被引量:6
1
作者 张静 王亚林 朱慕云 《临床肺科杂志》 2023年第4期541-545,共5页
目的评估膈肌偏移与老年慢阻肺患者肺低衰减区比例及肺功能之间的相关性,并探讨其对老年慢阻肺患者气流受限严重程度的判断价值。方法选取2020年6月到2021年12月在我院住院的慢阻肺急性加重期患者100例为研究对象,所有患者均行膈肌彩超... 目的评估膈肌偏移与老年慢阻肺患者肺低衰减区比例及肺功能之间的相关性,并探讨其对老年慢阻肺患者气流受限严重程度的判断价值。方法选取2020年6月到2021年12月在我院住院的慢阻肺急性加重期患者100例为研究对象,所有患者均行膈肌彩超、胸部高分辨率CT、肺功能检查,比较不同等级慢阻肺患者膈肌偏移、肺低衰减区比例(LAA%-950)及肺功能参数的差异,并进行相关性分析。结果1.100名慢阻肺患者GOLDⅠ级~Ⅳ级FEV_(1)%pred分别为:(85.48±2.98)%、(63.34±9.20)%、(42.95±5.74)%、(27.11±2.94)%,各GOLD组间肺功能参数:FEV_(1)%pred、FEV_(1)、FVC差异均有统计学意义(P<0.05);2.各GOLDⅠ级~Ⅳ级膈肌偏移分别为:(53.81±6.23)mm、(45.09±6.38)mm、(34.08±5.07)mm、(20.59±4.54)mm,各GOLD组间膈肌偏移差异均有统计学意义(P<0.05),且膈肌偏移随着GOLD分级的升高而降低;3.各GOLDⅠ级~Ⅳ级肺低衰减区域比例分别为:(8.02±5.78)%、(15.53±5.36)%、(18.62±2.75)%、(26.11±4.39)%,各GOLD组间差异有统计学差异(P<0.05),且LAA%-950随着GOLD分级的升高而升高。膈肌活动度与FEV_(1)%pred、FEV_(1)、FVC均呈正相关,其中FEV_(1)%pred与膈肌活动度的相关性最高,呈强相关(r>0.7),即FEV_(1)%pred越高,膈肌偏移越大;4.膈肌偏移与LAA%-950呈负相关(r<-0.7),即LAA%-950越高,膈肌活动度越差。结论膈肌偏移与慢阻肺患者肺低衰减区域及气流受限严重程度有显著相关性,肺过度充气导致膈肌活动度下降,膈肌活动度能够较准确的评估慢阻肺患者严重程度,可为患者早期诊断及预后干预提供客观性依据。 展开更多
关键词 慢性阻塞性肺疾病 膈肌偏移 肺低衰减比例 肺功能
下载PDF
CT所示低衰减区比例及肺容积评估肺通气功能受损程度的临床价值 被引量:3
2
作者 庞帅 蔡晓婷 +3 位作者 程挺 张能冲 倪瑾华 程齐俭 《上海交通大学学报(医学版)》 CAS CSCD 北大核心 2019年第11期1284-1292,共9页
目的·探讨通过胸部CT计算得到的低衰减区比例(ratio of low attenuation areas,LAA%)及肺容积对评估肺通气功能受损程度的临床价值。方法·回顾性纳入2010年1月—2014年7月在上海交通大学医学院附属瑞金医院同期完成胸部CT和... 目的·探讨通过胸部CT计算得到的低衰减区比例(ratio of low attenuation areas,LAA%)及肺容积对评估肺通气功能受损程度的临床价值。方法·回顾性纳入2010年1月—2014年7月在上海交通大学医学院附属瑞金医院同期完成胸部CT和肺通气功能检查的患者,用Myrian软件自动计算LAA%及肺容积,与舒张后第1秒用力呼气容积(forced expiratory volume in 1 second,FEV1)及其占预计值百分比(FEV1%pred)进行相关性分析,并纳入患者性别、年龄、身高、体质量建立回归方程。绘制ROC曲线,比较LAA%、肺容积及回归方程所得值在判断肺通气功能受损程度中的价值,根据约登指数和特异度选取界值,验证诊断效能。结果·纳入1150名受试者进入归纳组,LAA%与舒张后FEV1及FEV1%pred呈负相关,肺容积与舒张后FEV1呈正相关。舒张后FEV1的回归方程为:FEV1=-2.700+0.111×肺容积-0.216×ln(LAA%+0.1)-0.025×年龄+0.154×性别+0.034×身高。舒张后FEV1%pred的回归方程为:FEV1%pred=65.582+4.014×肺容积-7.508×ln(LAA%+0.1)-10.264×性别。在判断舒张后FEV1下降程度时,回归方程优于单独使用LAA%和肺容积;在判断舒张后FEV1%pred下降程度时,回归方程和LAA%优于肺容积。LAA%>1.61%用于判断舒张后FEV1%pred<35%的敏感度为75.6%,特异度为90.6%;舒张后FEV1的回归方程计算值<1.76用于判断舒张后FEV1<1 L的敏感度为58.9%,特异度为81.4%。结论·得到了基于胸部CT所示肺容积和LAA%的舒张后FEV1及FEV1%pred的回归方程,LAA%与肺容积可以粗略地估计肺通气功能的受损程度。 展开更多
关键词 计算机体层摄影术 肺容积 低衰减比例 肺功能 肺量计检查 第1秒用力呼气容积 慢性阻塞性肺疾病 肺气肿
下载PDF
提高机采井合理区比例 降低开采能耗 被引量:1
3
作者 孙东磊 《石油石化节能》 2012年第5期38-41,共4页
"十一五"以来,某油田X矿在机采井数迅速攀升、生产规模不断扩大、能耗控制难度加大的情况下,积极采取技术措施,加强管理,机采能耗水平得到有效控制,节能效果显著。具体生产中,油井在合理区运行,能耗会大大降低。动态控制图在... "十一五"以来,某油田X矿在机采井数迅速攀升、生产规模不断扩大、能耗控制难度加大的情况下,积极采取技术措施,加强管理,机采能耗水平得到有效控制,节能效果显著。具体生产中,油井在合理区运行,能耗会大大降低。动态控制图在油田应用已经近20年,因其对抽油机的科学化管理,从宏观到微观及时掌握每口井生产动态情况,能发掘措施潜力,为分析油井不合理运行提供依据。 展开更多
关键词 节能 合理比例 机采井
下载PDF
节水灌区指标体系与总效益评价方法探讨研究 被引量:10
4
作者 吕朝阳 郭宗楼 《节水灌溉》 北大核心 2008年第3期52-54,共3页
随着节水灌区建设规模日益增大,针对节水灌区的评价指标和评价效益的方法研究也在进一步深入。本文所介绍的方法是对灌区监测得到的信息及人为调查得来的信息进行综合分析研究,结合专家群决策以及AHP方法来确定权重系数,从而通过计算可... 随着节水灌区建设规模日益增大,针对节水灌区的评价指标和评价效益的方法研究也在进一步深入。本文所介绍的方法是对灌区监测得到的信息及人为调查得来的信息进行综合分析研究,结合专家群决策以及AHP方法来确定权重系数,从而通过计算可得到评价指标和评价效益相对应的评价数据,进而确定节水灌区建设及效益的满意程度。通过实例进行计算分析,得到较为满意的结果,可为灌区的策略性发展建设提供依据。 展开更多
关键词 节水灌 评价指标 评价效益 黄金效益比例区 满意度
下载PDF
上海地区办公建筑形态对单位能耗影响的研究
5
作者 刘瑞 于航 梁浩 《建筑热能通风空调》 2019年第2期42-45,10,共5页
本文提出"长宽比"(南北向长度与东西向长度的比值)和"内区比例"作为建筑形态的分类指标。以上海地区办公建筑为例,采用eQUEST建立了108个办公建筑模型,其中78个用于SPSS中进行回归分析,建立了能耗线性回归模型,30... 本文提出"长宽比"(南北向长度与东西向长度的比值)和"内区比例"作为建筑形态的分类指标。以上海地区办公建筑为例,采用eQUEST建立了108个办公建筑模型,其中78个用于SPSS中进行回归分析,建立了能耗线性回归模型,30个用于模型验证,获得了"长宽比"和"内区比例"与单位建筑面积能耗之间的数学关系,并与实际案例进行对比分析。结果表明:1)建立的回归模型可较好地量化建筑形态对单位建筑面积采暖供冷能耗和总能耗的影响。2)相同"内区比例"时,单位建筑面积能耗随着"长宽比"的减小而增大。3)相同"长宽比"时,单位建筑面积能耗随着"内区比例"的减小而增大。 展开更多
关键词 长宽比 比例 单位建筑面积能耗 能耗模拟 线性拟合
下载PDF
双辊薄带凝固组织的数值模拟(Ⅱ)——数学模型的应用 被引量:10
6
作者 杨明波 潘复生 +2 位作者 彭晓东 侯仕东 丁培道 《钢铁研究学报》 CAS CSCD 北大核心 2001年第5期30-34,共5页
双辊薄带凝固组织中柱状晶区所占比例对薄带质量有非常重要的影响。本文在已建数学模型的基础上 ,模拟预测了浇铸温度、铸辊转速、熔池高度等工艺参数对双辊薄带凝固组织中柱状晶区比例的影响。模拟结果表明 :在全凝固点位置位于铸辊出... 双辊薄带凝固组织中柱状晶区所占比例对薄带质量有非常重要的影响。本文在已建数学模型的基础上 ,模拟预测了浇铸温度、铸辊转速、熔池高度等工艺参数对双辊薄带凝固组织中柱状晶区比例的影响。模拟结果表明 :在全凝固点位置位于铸辊出口处和保持带厚不变的条件下 。 展开更多
关键词 双辊薄带连铸 柱状晶比例 工艺参数 凝固组织 数学模型
下载PDF
日本大选后组成新政府
7
作者 马俊威 《国际研究参考》 1996年第12期23-24,共2页
1996年10月20日,日本第41届众议院大选揭晓,无一政党取得半数以上议席。自民党击败老对手新进党取得运筹政局的主导权。11月7日,自民党总裁桥本龙太郎得到社民党等党派的支持,在特别国会的第一轮选举中以多数票当选日本第83任内阁总理大... 1996年10月20日,日本第41届众议院大选揭晓,无一政党取得半数以上议席。自民党击败老对手新进党取得运筹政局的主导权。11月7日,自民党总裁桥本龙太郎得到社民党等党派的支持,在特别国会的第一轮选举中以多数票当选日本第83任内阁总理大臣,随即组成自民党少数派内阁。 展开更多
关键词 自民党 行政改革 社民党 民主党 日本 中选举 内阁总理大臣 桥本内阁 新政 比例区
下载PDF
数字化加热炉在石钢的应用 被引量:1
8
作者 孙运芝 池宪华 《河北冶金》 2006年第1期48-49,60,共3页
介绍了数字化加热炉的特点及优点,并和传统比例加热炉作了比较。
关键词 数字化 加热炉 比例加热炉虚拟 时序脉冲燃烧 优化燃烧 模糊逻辑控制
下载PDF
干湿联合冷却塔消雾节水特性的耦合研究 被引量:8
9
作者 陈铁锋 胡少华 +2 位作者 赵元宾 高沙沙 刘忠超 《中国电机工程学报》 EI CSCD 北大核心 2021年第1期277-287,共11页
随着节水、减排、环保等问题的日益严峻,消雾节水型冷却塔逐渐受重视。针对消雾节水型干湿联合冷却塔,建立其传热传质过程气水参数变化的理论计算模型,根据其出塔空气与环境空气掺混过程参数变化,计算分析其成雾特性、蒸发水量,并结合... 随着节水、减排、环保等问题的日益严峻,消雾节水型冷却塔逐渐受重视。针对消雾节水型干湿联合冷却塔,建立其传热传质过程气水参数变化的理论计算模型,根据其出塔空气与环境空气掺混过程参数变化,计算分析其成雾特性、蒸发水量,并结合文献数据验证了计算模型的正确性。对标干湿联合冷却塔消雾验收测试的典型规程,通过出塔空气干湿球温度曲线、最大相对湿度曲线、成雾频率曲线和塔雾指数等,结合某干湿联合冷却塔实测数据,分析了干区进水比例对消雾特性、节水特性、冷却特性的影响。对所研究工况,百叶窗全开时干区进水比例越高,干湿联合冷却塔的消雾节水性能及冷却性能越好,为干湿联合冷却塔的设计优化和运行优化提供了参考和指导。 展开更多
关键词 干湿联合冷却塔 消雾特性 节水特性 冷却特性 耦合研究 进水比例
下载PDF
Investigation into co-pyrolysis characteristics of oil shale and coal 被引量:10
10
作者 Miao Zhenyong Wu Guoguang +2 位作者 Li Ping Meng Xianliang Zheng Zhilei 《International Journal of Mining Science and Technology》 2012年第2期245-249,共5页
Samples of five types of coal and oil shale from the Daqing region have been subjected to co-pyrolysis in different blending ratios with thermo-gravimetry (TG), given a heating rate of 30 ℃/min to a final tem- pera... Samples of five types of coal and oil shale from the Daqing region have been subjected to co-pyrolysis in different blending ratios with thermo-gravimetry (TG), given a heating rate of 30 ℃/min to a final tem- perature of 900 ℃. Investigations on pyrolysis of mixing coal and oil shale in different proportions were carried out, indicating that the main scope of weight loss corresponding to hydrocarbon oil and gas release was between 350 and 550 ℃. At higher temperatures, significant weight loss was attributed to coke decomposition. Characteristic pyrolysis parameters of blends from oil shale and the high ranked XZ coal varied with the blending ratio, but oil shale dominated the process. At the same blending propor- tions, highly volatile medium and low ranked coal of low moisture and ash content reacted well during pyrolysis and could easily create synergies with oil shale. Medium and high ranked coal with high mois- ture content played a negative role in co-pyrolysis. 展开更多
关键词 Oil shaleCo-pyrolysisBlending coal samplesBlending ratio
下载PDF
Comparison of Development of Housing Construction in Regions of Slovakia and Czech Republic
11
作者 Zora Petrakova Martina Jurigova Jan Dvorsky 《Chinese Business Review》 2016年第6期282-289,共8页
Cities and municipalities are involved in the economic development of the whole country. One of the priorities of mayors is the usefulness of spatial disproportions of area as well as the structure and development of ... Cities and municipalities are involved in the economic development of the whole country. One of the priorities of mayors is the usefulness of spatial disproportions of area as well as the structure and development of housing construction. They are natural canters of public and commercial services. The aim of the article is to determine if the geographic location of the region influences the number of new apartments with planning permission and completed apartments with a completion approval by using the methods of mathematical statistics "Analysis of variance". Meaning of the geographical location of the region as a factor, which influences the construction of apartments as well as regional differences in selected Central European countries, is subject of the conclusions of the paper. 展开更多
关键词 region analysis of variance planning permission completion approval development of housing Kruskal-Wallis test
下载PDF
Effects of Row Spacing on Component, Biomass and Energy of Elymus sibiricus L.
12
作者 Jinping Liu Minghong You 《Journal of Environmental Science and Engineering(A)》 2013年第10期617-624,共8页
In the study, E. sibiricus L. cv. chuancao No. 2 was allocated to plots in a randomized block design with five row gradients (30, 45, 60, 75 and 90 cm). At the flowering stage, the root, stem, leaf and inflorescence... In the study, E. sibiricus L. cv. chuancao No. 2 was allocated to plots in a randomized block design with five row gradients (30, 45, 60, 75 and 90 cm). At the flowering stage, the root, stem, leaf and inflorescence of population, as well as the quantitative traits of components, biomass structure, accumulation and distribution proportion of energy were measured and analyzed. For different row spacings, there are highly significant differences between total tillers and ratio of fertile tillers per square meter and significant differences among the eustipes length, eustipes number and natural height of each tiller; but there are no significant differences among the leaf length, leaf width and leaf number of each tiller. A significant difference is found between the depth and distribution range of root, inflorescence stalk, and ear number of fertile tillers, and the biomass of leaf, stem, root and inflorescence. The influenced order is stem 〉 leave 〉 root 〉 inflorescence. No significant influence is found among the energy values of single leaf, stem, root and inflorescence; but a significant influence is found among the energy accumulation of the leaf, stem, root and inflorescence with the effect degree being stem 〉 leaf 〉 inflorescence 〉 root. Significant differences are also found among the energy distribution of each component with the order of leaf〉 stem 〉 inflorescence 〉 root. 展开更多
关键词 Biomass structure COMPONENT Elymus sibiricus L. ENERGY row space.
下载PDF
异步轧制搓轧区几何参数 被引量:9
13
作者 汤德林 刘相华 《钢铁》 CAS CSCD 北大核心 2015年第4期34-39,共6页
为研究异步轧制搓轧区的几何参数,根据力平衡方程和秒流量相等的原则,建立了无张力条件下不同变形区组态的中性角和搓轧区比例计算模型,并按中性角取值对不同变形区组态进行划分。在三区组态的条件下,分析讨论了异速比、摩擦因数、轧件... 为研究异步轧制搓轧区的几何参数,根据力平衡方程和秒流量相等的原则,建立了无张力条件下不同变形区组态的中性角和搓轧区比例计算模型,并按中性角取值对不同变形区组态进行划分。在三区组态的条件下,分析讨论了异速比、摩擦因数、轧件厚度和压下率对搓轧区比例的影响。搓轧区比例是决定异步轧制在降低轧制力、最小可轧厚度和得到细化组织工艺条件的重要参数,搓轧区比例计算模型的建立,为异步轧制工艺参数的设定提供了理论依据。中性角和搓轧区比例计算式经过试验验证,与实际值吻合。 展开更多
关键词 异步轧制 变形组态 中性角 搓轧比例
原文传递
我对“比例”的看法
14
作者 周永林 《中小学数学(小学版)》 2008年第6期41-42,共2页
《中小学数学》小学版2007第7、8期刊载了薛雪原老师的文章——《比例改变了吗?》(以下称《比例》)。在《比例》中,薛老师针对根据等式3×40=8×15可以写出几个不同比例的问题,提出了"相同比例"和"不同比例"... 《中小学数学》小学版2007第7、8期刊载了薛雪原老师的文章——《比例改变了吗?》(以下称《比例》)。在《比例》中,薛老师针对根据等式3×40=8×15可以写出几个不同比例的问题,提出了"相同比例"和"不同比例"的问题,认为根据等式3×40=8×15只可以写出4个不同的比例。 展开更多
关键词 不同比例 比例区 中小学数学 老师 外项 看法 内项 比值 等式 观点
原文传递
大规模多中段矿体回采顺序优化研究 被引量:4
15
作者 尚振华 朱青凌 詹文欢 《矿业研究与开发》 CAS 北大核心 2015年第11期5-8,共4页
传统数值模拟分析方法主要采用定量分析模型的位移和应力、定性分析模型的塑性区,因而在多个相似方案比较时,经常会出现定量结果很相近而定性结果的说服力又不强的尴尬局面。为此,提出塑性区量化的"破坏比例"概念来解决优化... 传统数值模拟分析方法主要采用定量分析模型的位移和应力、定性分析模型的塑性区,因而在多个相似方案比较时,经常会出现定量结果很相近而定性结果的说服力又不强的尴尬局面。为此,提出塑性区量化的"破坏比例"概念来解决优化方案区分问题。在FLAC3D数值模拟的基础上,采用FISH语言编程,统计得出研究区域的位移、应力和塑性区"破坏比例",实际案例应用证明,综合传统的分析方法和"破坏比例"法分析模拟结果,各方案的优缺点一目了然,这一改进方法也弥补了数值模拟软件在塑性区分析时只能定性的不足。 展开更多
关键词 数值模拟 塑性破坏比例 回采顺序 方案优化
原文传递
日本大选及政局动向
16
作者 俊平 《瞭望》 北大核心 1996年第45期43-44,共2页
10月20日,日本第41届众院大选揭晓,现政党无一取得众院半数以上议席。自民党击败老对手新进党取得运筹政局的主导权,以自民党为主的联合政权框架将继续维持,桥本龙太郎连任首相已成定局。 在20日的大选中,日本各政党共推荐了1503名候选... 10月20日,日本第41届众院大选揭晓,现政党无一取得众院半数以上议席。自民党击败老对手新进党取得运筹政局的主导权,以自民党为主的联合政权框架将继续维持,桥本龙太郎连任首相已成定局。 在20日的大选中,日本各政党共推荐了1503名候选人,争夺众院的500个议席。自民党获胜,取得239席,比选举前增28席,从而确保了第一大党的地位,并向单独执政的251席目标大大地迈进了一步;新进党受挫,取得156席,减5席。 展开更多
关键词 自民党 中选举 民主党 日本共产党 社民党 比例代表 比例区 联合国 候选人 政党
原文传递
The sex ratio of wild Chinese alligators Alligator sinensis 被引量:4
17
作者 Lan ZHAO Hai-Qiong YANG +5 位作者 Li-Ming FANG Guo-Liang PAN Wei-Qiang ZOU Da-Bin REN Qiu-Hong WAN Sheng-Guo FANG 《Current Zoology》 SCIE CAS CSCD 2013年第6期725-731,共7页
The Chinese alligator Alligator sinensis is one of the most endangered crocodilian species, and typically exhibits temperature-dependent sex determination. It is extremely important to clarify the sex structure of Chi... The Chinese alligator Alligator sinensis is one of the most endangered crocodilian species, and typically exhibits temperature-dependent sex determination. It is extremely important to clarify the sex structure of Chinese alligators to implement recovery projects successfully. However, the sex ratio of wild Chinese alligators remains unknown. In this study, we collected 28 years of sex ratio data from Chinese alligators residing in the natural and artificial habitats of Changxing Nature Reserve, China, and examined the differences in the sex ratio dynamics between these two populations. We observed that the sex ratio of wild Chinese alligators is 1 male to 4.507 females, which was significantly lower compared to that of the captive population (1 to 2.040; P 〈 0.001), and is significantly different to previously documented sex ratios for this species (all P 〈 0.01). Furthermore, we documented an annually stable (P = 1.000) female-biased sex ratio for wild alligators at hatching [1 male to 4.747 females; 0.174 (0.167~).182)], in contrast to a dramatically fluctuating sex ratio (P 〈 0.001) in captivity [1 male to 1.674 females; 0.374 (0.246-0.593)], showing a potential mechanism for adjusting the sex structure. Finally, we found that the hatchling sex ratios were similar to that of the population sex ratio (P = 0.748), with little correlation to air temperature values in the 60-70 day incubation period during the breeding season (July and August; both P 〉 0.05). Overall, this study indicates that the stabilized female-biased sex ratio of Changxing Chinese alligators might result from selection pressure caused by local mate competition and major inbreeding . 展开更多
关键词 REPTILE Female-biased Temperature-dependent sex determination Conservation
原文传递
In-situ measurement of atmospheric CFC-11 at the Shangdianzi Global Atmosphere Watch(GAW) Regional Station 被引量:1
18
作者 ZHANG Fang ZHOU LingXi +6 位作者 YAO Bo ZHANG XiaoChun XU Lin ZHANG XiaoLing ZHOU HuaiGang DONG Fan ZHOU LiYan 《Science China Earth Sciences》 SCIE EI CAS 2011年第2期298-304,共7页
An in-situ GC-ECD system was used to measure halocarbons at Shangdianzi (SDZ) GAW regional station. In this paper, we reported observational results of atmospheric CFC- 11 (CCI3F) mixing ratios from April 2007 to ... An in-situ GC-ECD system was used to measure halocarbons at Shangdianzi (SDZ) GAW regional station. In this paper, we reported observational results of atmospheric CFC- 11 (CCI3F) mixing ratios from April 2007 to March 2008. The CFC- 11 time series showed large variability. Approximately 62% observed values were filtered as non-background data. The median, 10% and 90% percentiles of CFC-11 background mixing ratios were 245.4 ppt (10-12 mol/mol), 244.6 ppt and 246.1 ppt, respectively; whereas those of non-background CFC- 11 mixing ratios were 254.7, 246.6 and 272.1 ppt, respectively. Significant differences in background and non-background CFC-11 mixing ratios were observed between summer and autumn, mainly because of the CFC-11 stored in loam being prone to atmospheric release in hot seasons. Comparison of tile SDZ data with the five AGAGE stations suggested agreement with mid-high latitude Northern Hemisphere stations MHD, THD and RPB. The SDZ data were higher than that of Southern Hemisphere stations CGO and SMO. Higher CFC-11 mixing ratios measured in different seasons were always associated with winds from the W-WSW-SW sector, indicating that the airflow coming from this wind sector has a positive contribution to CFC- 11 concentrations. The CFC-11 mixing ratios were higher in autumn and summer than in spring and winter, in which its mixing ratios were very close to the atmospheric background level. This was happened especially when airflow originated from the NNE-NE-ENE-E sector, indicating the air masses coming from these wind directions was relatively clean. 展开更多
关键词 SDZ background CFC-11 seasonal variation winds
原文传递
Derivation and analysis on the analytical structure of interval type-2 fuzzy controller with two nonlinear fuzzy sets for each input variable
19
作者 Bin-bin LEI Xue-chao DUAN +1 位作者 Hong BAO Qian XU 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第6期587-602,共16页
Type-2 fuzzy controllers have been mostly viewed as black-box function generators. Revealing the analytical structure of any type-2 fuzzy controller is important as it will deepen our understanding of how and why a ty... Type-2 fuzzy controllers have been mostly viewed as black-box function generators. Revealing the analytical structure of any type-2 fuzzy controller is important as it will deepen our understanding of how and why a type-2 fuzzy controller functions and lay a foundation for more rigorous system analysis and design. In this study, we derive and analyze the analytical structure of an interval type-2 fuzzy controller that uses the following identical elements: two nonlinear interval type-2 input fuzzy sets for each variable, four interval type-2 singleton output fuzzy sets, a Zadeh AND operator, and the Karnik-Mendel type reducer. Through dividing the input space of the interval type-2 fuzzy controller into 15 partitions, the input-output relationship for each local region is derived. Our derivation shows explicitly that the controller is approximately equivalent to a nonlinear proportional integral or proportional differential controller with variable gains. Furthermore, by comparing with the analytical structure of its type-1 counterpart, potential advantages of the interval type-2 fuzzy controller are analyzed. Finally, the reliability of the analysis results and the effectiveness of the interval type-2 fuzzy controller are verified by a simulation and an experiment. 展开更多
关键词 Interval type-2 fuzzy controller Analytical structure Karnik-Mendel type reducer
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部