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居民就诊次数的Hurdle模型分析 被引量:6
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作者 曾平 赵晋芳 刘桂芬 《中国卫生统计》 CSCD 北大核心 2010年第6期603-605,共3页
目的介绍Hurdle模型及其在医学零过多计数资料中的应用。方法采用logit-Poisson Hurdle模型分析2周内居民就诊次数的数据。结果居民决定是否去医院就诊存在性别和年龄的差异;居民的收入、两周内患病次数、疾病导致的活动减少天数是影响... 目的介绍Hurdle模型及其在医学零过多计数资料中的应用。方法采用logit-Poisson Hurdle模型分析2周内居民就诊次数的数据。结果居民决定是否去医院就诊存在性别和年龄的差异;居民的收入、两周内患病次数、疾病导致的活动减少天数是影响过去2周内就诊次数多少的主要因素。结论 Hurdle模型可有效分析零过多计数资料。 展开更多
关键词 计数资料 零过多 hurdle模型 就诊次数
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Hurdle模型及其在居民就诊影响因素中的应用 被引量:5
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作者 赵丽华 刘桂芬 +1 位作者 原静 曾平 《中国卫生统计》 CSCD 北大核心 2010年第2期149-151,共3页
目的阐明Hurdle模型原理及其在计数资料中的应用。方法利用logit-Poisson Hurdle模型分析两周内居民就诊次数的影响因素。结果 Hurdle模型logistic回归部分结果表明,性别、年龄和经济收入是决定居民是否去医院就诊的主要因素,零截尾Pois... 目的阐明Hurdle模型原理及其在计数资料中的应用。方法利用logit-Poisson Hurdle模型分析两周内居民就诊次数的影响因素。结果 Hurdle模型logistic回归部分结果表明,性别、年龄和经济收入是决定居民是否去医院就诊的主要因素,零截尾Poisson部分结果表明两周内患病次数、由疾病而导致活动天数减少是影响两周内居民就诊次数的主要因素。结论 Hurdle模型是处理零频数过多计数资料一种有效可行的方法 ,其参数估计准确,分析结果切合实际、解释合理。 展开更多
关键词 hurdle模型 计数资料 零频数过多
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基于logit-NB Hurdle模型阳性过敏原数的影响因素分析 被引量:1
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作者 刘妍妍 李萌 +3 位作者 于磊 王蕊 张茂祥 刘美娜 《中国医院统计》 2015年第6期415-418,共4页
目的应用Hurdle模型分析具有零膨胀数据阳性过敏原数的影响因素,为预防过敏反应及过敏性疾病提供依据。方法收集2014年就诊变态反应科的患者1855例,以问卷调查方式获得患者基本信息,测定血清过敏原特异性IgE获得阳性过敏原数;应用lo... 目的应用Hurdle模型分析具有零膨胀数据阳性过敏原数的影响因素,为预防过敏反应及过敏性疾病提供依据。方法收集2014年就诊变态反应科的患者1855例,以问卷调查方式获得患者基本信息,测定血清过敏原特异性IgE获得阳性过敏原数;应用logit.NBHurdle模型分析阳性过敏原数的影响因素。结果在就诊患者中,阳性过敏原数为0的患者占72.29%,数据具零膨胀现象。两次Voung检验的y值分别为3.90、2.77,P值均小于0.05,logit—PoissonHurdle和logit.NBHurdle优于传统计数模型;logit-PoissonHurdle和logit—NBHurdle的似然比检验LR=205,P〈0.05,结合AIC=1898.6、AICC=1900.3、肌=2042.4的结果,选择logit.NBHurdle为最优模型。Logit部分结果为女性比男性更易发生过敏反应;零截尾负二项部分结果为过敏原数目与文化程度、母亲有过敏史有关,文化程度低、母亲有过敏史的患者过敏原数多。结论分析零膨胀过离散数据前需要进行最优模型的选择;女性是过敏反应的好发人群,预防人群的阳性过敏原数多更应关注母亲有过敏史及文化程度低的人群。 展开更多
关键词 hurdle模型 阳性过敏原数 影响因素
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孤独症研究中Hurdle模型的变量选择方法
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作者 刘成烽 李姣 +3 位作者 王学钦 易莉 冯聪 谭海珠 《中山大学学报(医学科学版)》 CAS CSCD 北大核心 2015年第4期505-511,共7页
【目的】在研究孤独症等心理学课题的研究过程中,我们经常会碰到一类计数数据,它们会呈现过度离散和零度膨胀等特征。为了探索影响孤独症的真正影响因素,本文提出一种全新的基于Hurdle模型基础上的自适应LASSO变量选择方法 Hurdle-ALAS... 【目的】在研究孤独症等心理学课题的研究过程中,我们经常会碰到一类计数数据,它们会呈现过度离散和零度膨胀等特征。为了探索影响孤独症的真正影响因素,本文提出一种全新的基于Hurdle模型基础上的自适应LASSO变量选择方法 Hurdle-ALASSO,用于实现对这类计数数据的变量选择。【方法】对24名孤独症患者、26名精神发育迟滞患者和28名正常人士分别进行面部识别实验,分别记录他们的眼动轨迹计数数据。利用Hurdle-ALASSO方法对三组具有过度离散和零膨胀特征的眼动轨迹计数数据进行重要变量的筛选。【结果】影响参与者面孔识别的主要因素包括观察路径、注视面孔时间和注视脸部各部位的时间比例。孤独症患者脸部识别的认知过程与精神发育迟滞患者和正常人士相比存在差异,且路径扫视次数并不是导致差异的因素。【结论】Hurdle-ALASSO方法能有效地实现对具有零膨胀和过度离散特征的心理学类计数数据进行变量选择。 展开更多
关键词 孤独症 过度离散 零膨胀 计数数据 hurdle模型 自适应LASSO 变量选择
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Effect of socio-demographic status on dental caries in pupils by using a multilevel hurdle model
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作者 Yunes Jahani Mohammad R. Eshraghian +4 位作者 Abbas R. Foroushani Keramat Nourijelyani Kazem Mohammad Arash Shahravan Mahin Alam 《Health》 2013年第7期1110-1116,共7页
Introduction: Dental caries is the most prevalent chronic disease among schoolchildren. We aimed to investigate the association between dental caries index and socio-demographic status in schoolchildren by using a mul... Introduction: Dental caries is the most prevalent chronic disease among schoolchildren. We aimed to investigate the association between dental caries index and socio-demographic status in schoolchildren by using a multilevel hurdle model. Materials and Methods: A cross-sectional epidemiological study was carried out on 906 primary school pupils in Kerman, Iran in 2012. The subjects were selected through a stratified cluster random sampling. At first, the whole target area was stratified according to two geographic areas, the north and south area. Then each area was stratified according to gender. In the next step, several schools were considered as clusters, which were selected randomly in each geographic area and gender strata. All the schoolchildren in these schools were included in this study as samples. Twelve-year-old pupils were examined for dental caries. The dependent variable in this study was the dmft/DMFT index. Eight variables, including socio-demographic information, were collected. Multilevel negative binomial hurdle model was employed for data analysis. Results: The prevalence of caries-free pupils was 30.1% and the mean dmft/DMFT was 3.6 ± 2.2. Negative binomial part of the adjusted model showed that the dmft/DMFT adjusted rate for females was 1.36 (95% CI: 1.10-1.79) times higher than males. Also, the dmft/DMFT adjusted rate for overweight pupils was 0.86 (95% CI: 0.74-0.98) times lower than those with normal weight. Logistic part of the adjusted model showed that the posibility of caries-free state in overweight pupils was 1.95 (95% CI: 1.22-3.11) times higher than those with normal weight. In addition, pupils whose fathers and mothers were workers and housewives, respectively, and those with a high maternal age were at a greater risk for caries experience than others (p < 0.05). Conclusion: BMI, gender, parent’s job and mother’s age at delivery were factors effecting on dental caries in schoolchildren. These pupils need more attention to dental care. 展开更多
关键词 MULTILEVEL hurdle Model Dental Caries SOCIO-DEMOGRAPHIC STATUS Primary School PUPILS dmft/DMFT Index
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A Hurdle Negative Binomial Regression Model for Non-Marital Fertility in Namibia
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作者 Lillian Pazvakawambwa Nelago Indongo Lawrence Kazembe 《Journal of Mathematics and System Science》 2014年第7期498-508,共11页
The rise of non-marital fertility, which seems to defy the Bongaarts model by decoupling marriage from fertility, has become a subject of interest in both the developed and developing world. Consequences of non-marita... The rise of non-marital fertility, which seems to defy the Bongaarts model by decoupling marriage from fertility, has become a subject of interest in both the developed and developing world. Consequences of non-marital fertility are mostly negative particularly in developing countries. In Namibia, although premarital childbearing has been reported to be high and increasing, no studies have explicitly analyzed factors influencing non-marital fertility. This paper uses data from the 2006/7 Namibia DHS to establish the determinants of non-marital fertility among women by applying a two-part model, with one part to describe the presence of non-marital birth and the other part to explain its intensity (number of children born). Using the number of children ever born as an outcome, we explored various count data models. Based on the Voung statistics model comparison, we settled for the Hurdle logit Negative Binomial regression to model the number of non-marital births. Non-marital fertility in Namibia is associated with the age, with young women likely to have lower fertility compared to older women. Women with secondary or higher education had lower fertility compared those with no formal education. Findings also show that rural women higher fertility propensity compared to their urban counterparts even though there was no significant difference in fertility intensity. With regard to socio-economic status, fertility intensity decreased as the women got richer. Intervention efforts should focus on promoting education among girls and women especially in rural areas to improve their socio-economic status, reduce teenage pregnancy and non-marital fertility. 展开更多
关键词 non-marital fertility hurdle logit negative binomial two-part models Namibia
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Russia Clears Last Hurdle for W.T.O. Membership
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作者 New York Times 《China's Foreign Trade》 2011年第23期30-30,共1页
Russia on November 10 cleared the last major obstacle in its 18-year effort to join the World Trade Organization in what the head of the institution called a milestone for global trade. "It’s a victory for Russi... Russia on November 10 cleared the last major obstacle in its 18-year effort to join the World Trade Organization in what the head of the institution called a milestone for global trade. "It’s a victory for Russia, a victory for W.T.O. members, and a victory 展开更多
关键词 MEMBERSHIP Russia Clears Last hurdle for W.T.O
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Understanding parental hurdles in accessing strabismus treatment
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作者 Omna Chawla Anupam Singh +5 位作者 Himani Pal Sanjeev Kumar Mittal Srishti Sharma Mittali Khurana Pooja Kumari Barun Kumar 《Advances in Ophthalmology Practice and Research》 2024年第4期189-193,共5页
Purpose:To explore the parental factors that impede early intervention for strabismus and thus identify strategies for improving access to specialized care.Methods:This hospital-based cross-sectional study included 11... Purpose:To explore the parental factors that impede early intervention for strabismus and thus identify strategies for improving access to specialized care.Methods:This hospital-based cross-sectional study included 110 parents of children under 19 years with strabismus receiving treatment at the squint clinic of a tertiary health care center in north India.A pre-validated survey questionnaire was administered to the participants,that had a section about the socio-demographics of the participants,another section addressed the parental knowledge about strabismus about diagnosis,and the need for an eye examination.It also sought information about referral source,the felt need for squint examination,and reasons for not seeking treatment.Results:A total of 110 parents/guardians of strabismus patients(59 exotropes and 51 esotropes)were interviewed using a survey questionnaire.Parents themselves identified 80%of cases,and a substantial link(P<0.0001)was found between the education status of parents and the age of identification of strabismus.Fear of surgical outcomes(41.79%)was a significant barrier to timely surgery with a higher percentage of parents expressing fear of surgical outcomes(P=0.025).The cost of surgery(34.33%)and the non-availability of facilities(23.88%)also delayed the intervention.Conclusions:It is essential to educate parents about the importance of strabismus therapy at an appropriate time,stressing its reconstructive rather than merely cosmetic nature,as there are notable gaps in their knowledge.Also,we need to do away with the fear of surgical outcomes of surgical interventions for strabismus. 展开更多
关键词 PARENTAL STRABISMUS hurdles TREATMENT SURVEY
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农户病虫害综合防治技术的采纳决策和采纳密度研究——基于Double-Hurdle模型的实证分析 被引量:68
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作者 储成兵 《农业技术经济》 CSSCI 北大核心 2015年第9期117-127,共11页
本文利用安徽省7个县402户农户的调研数据,基于Double-Hurdle模型对农户IPM技术的采纳决策和采纳密度进行了实证分析。研究结果表明,显著影响农户IPM技术的采纳决定和采纳密度的因素具有一定的差异。户主文化程度、环保意识、参加IPM技... 本文利用安徽省7个县402户农户的调研数据,基于Double-Hurdle模型对农户IPM技术的采纳决策和采纳密度进行了实证分析。研究结果表明,显著影响农户IPM技术的采纳决定和采纳密度的因素具有一定的差异。户主文化程度、环保意识、参加IPM技术的培训、非农收入占比、农业信息的获取及贷款的可获性显著促进农户对IPM技术的采纳,而户主性别与风险偏好类型则显著负向影响农户对IPM技术的采纳。显著促进农户IPM技术采纳密度的因素有户主性别、文化程度及农业信息的获取,而农户风险偏好类型则呈负向作用。最后根据实证研究结果提出相应的政策建议。 展开更多
关键词 IPM技术 采纳密度 农户Double.hurdle模型
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气候敏感的杉木天然林林分进界模型
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作者 何江 覃林 《林业科学》 北大核心 2025年第1期70-80,共11页
【目的】构建气候敏感的杉木天然林林分进界模型,为该区域天然次生林实施科学修复和抚育措施进而提高林分质量、助力“双碳”战略目标实现提供科学指导。【方法】基于湖南省第八次(2009年)和第九次(2014年)国家森林资源连续清查数据,筛... 【目的】构建气候敏感的杉木天然林林分进界模型,为该区域天然次生林实施科学修复和抚育措施进而提高林分质量、助力“双碳”战略目标实现提供科学指导。【方法】基于湖南省第八次(2009年)和第九次(2014年)国家森林资源连续清查数据,筛选出杉木天然林样地784块,选取林分因子、立地因子和气象因子作为协变量,以负二项(NB)模型为基础模型,考虑到进界数据过度离散的特点,引入零膨胀模型和Hurdle模型,构建零膨胀泊松(ZIP)模型、零膨胀负二项(ZINB)模型、Hurdle-泊松(HP)模型和Hurdle-负二项(HNB)模型。为解决重复测量和分层导致可能存在的数据自相关性和异方差性问题,在上述5种模型基础上,引入样地所在县域作为随机效应,构建广义非线性混合效应模型,采用十折交叉验证法对模型进行检验。【结果】单木所属树种的胸高断面积(Bai)、土层厚度(ST)、海拔(EL)和年均降水量(MAP)均显著影响杉木林分进界。负二项复合模型(NB、ZINB和HNB模型)在模拟杉木林分进界方面的表现明显优于泊松复合模型(ZIP和HP模型);ZINB和HNB模型的拟合效果优于NB模型,ZINB模型的拟合效果略优于HNB模型;引入县域随机效应后,NB、ZIP、ZINB和HP模型的拟合效果均显著优于基础模型,其中以ZINB混合效应模型拟合效果最好,十折交叉验证结果进一步证明混合效应模型优于基础模型。【结论】单木所属树种的胸高断面积、土层厚度、海拔和年均降水量是影响林木进界概率和数量的重要因子,构建的气候敏感的杉木天然林林分进界模型具有一定生物学意义和统计可靠性,可为该区域气候变化背景下的天然次生林生态修复和中幼林抚育间伐提供科学依据,有助于精准提升森林质量,助力“双碳”战略目标如期实现。 展开更多
关键词 杉木 林分进界 零膨胀模型 hurdle模型 混合效应模型
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帽儿山天然林进界模型及影响因素分析
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作者 刘佳琦 董利虎 苗铮 《森林工程》 北大核心 2025年第5期871-882,共12页
林分进界是林分生长动态变化过程中的一个重要环节,对于维持森林资源中的生物多样性和群落结构稳定至关重要。为此,在帽儿山实验林场设立的61块样地数据,从林分因子及生物多样性因子等方面进行考虑,通过肯德尔tau-b(Kendall-Tau-b)相关... 林分进界是林分生长动态变化过程中的一个重要环节,对于维持森林资源中的生物多样性和群落结构稳定至关重要。为此,在帽儿山实验林场设立的61块样地数据,从林分因子及生物多样性因子等方面进行考虑,通过肯德尔tau-b(Kendall-Tau-b)相关系数分析及考虑变量多重共线性选择最适变量,采用泊松(Poisson)模型、负二项模型(negative binomial model,NB)、零膨胀模型及障碍(Hurdle)模型构建进界模型。采用层次分割法分析变量贡献率,以找出影响进界模型的关键因素。研究结果表明,林分拥挤度(K)、林分算数平均胸径(d)、辛普森(Simpson)指数和林分平均高(mean height,MH)是影响每公顷进界株数(number of advance regeneration per hectare,Nn)的重要因子。通过赤池信息准则(akaike information criterion,AIC)、贝叶斯信息准则(bayesian information criterion,BIC)及对数似然值(logarithm likelihood,Loglike)指标对比,发现零膨胀负二项式(zero-inflated negative binomial,ZINB)模型与障碍负二项(hurdle negative binomial,HNB)模型显著优于其他模型。通过沃恩(Vuong)检验,发现负二项模型及其复合模型(ZINB、HNB)在拟合帽儿山天然林进界数量方面优于Poisson模型及其复合模型(零膨胀泊松模型(zero-inflated poisson model,ZIP)、障碍泊松模型(hurdle poisson model,HP)),且ZINB模型略优于HNB模型,故ZINB模型为拟合帽儿山天然林林分进界数量的最优模型,十折交叉检验也验证了这一结论。同时,通过层次分割法分析发现Simpson指数和林分平均高(MH)分别对最优进界模型(ZINB)的计数部分和零部分贡献度最高。所构建的帽儿山天然林进界模型具有一定的统计可靠性,可用于该地区进界生长预测,为当地天然林更新管理提供科学依据。 展开更多
关键词 进界 Kendall-Tau-b 零膨胀模型 hurdle模型 层次分割
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四川都江堰离堆公园半寄生植物分布及影响因素
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作者 郑炜 王靖岚 +4 位作者 刘英 Benjamin Laffitte 周瑾 曾敏 唐亚 《四川林业科技》 2025年第5期93-102,共10页
园林树木是城市生态系统的重要组成部分,调查了解园林树木的半寄生植物(桑寄生科和槲寄生属)分布并进行影响因素研究十分必要。调查四川都江堰离堆公园的半寄生植物发现,1362株木本植物中有21科30属30种171株成为半寄生植物的寄主植物,... 园林树木是城市生态系统的重要组成部分,调查了解园林树木的半寄生植物(桑寄生科和槲寄生属)分布并进行影响因素研究十分必要。调查四川都江堰离堆公园的半寄生植物发现,1362株木本植物中有21科30属30种171株成为半寄生植物的寄主植物,总寄生率达12.8%;寄生植物总丛数有490丛,平均寄生强度为2.8丛。寄生植物主要分布在邻水和邻低矮建筑的开阔区域,寄生率和寄生偏好最大的物种是杜梨、皂荚、构树、垂柳、枫杨、水杉。有五个变量与寄生率呈正相关(落叶、高度、胸径、邻水、邻建筑),一个变量(可供鸟类食用)与寄生率呈负相关,另有三个变量(高度、落叶、可供鸟类食用)与寄生强度正相关。建议有针对性地清除离堆公园古树上的半寄生植物,并进一步开展半寄生植物影响效应研究,科学维护离堆公园的生物多样性。 展开更多
关键词 离堆公园 半寄生植物 寄生率 寄生强度 hurdle模型
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Hurdle technology for fish preservation 被引量:6
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作者 Theofania Tsironi Dimitra Houhoula Petros Taoukis 《Aquaculture and Fisheries》 2020年第2期65-71,共7页
Fresh fish is a highly perishable product due to the chemical composition of fish flesh and the high microbial load on fish surface.The natural microflora that is more adopted to low temperatures results also in lower... Fresh fish is a highly perishable product due to the chemical composition of fish flesh and the high microbial load on fish surface.The natural microflora that is more adopted to low temperatures results also in lower thermal bacterial shock from natural temperature to the preservation temperature range.The development of new fish processing(e.g.high hydrostatic pressure,osmotic dehydration,high-intensity pulsed light)and packaging(e.g.modified atmospheres,active and intelligent packaging)methods or novel combinations of existing technologies is sought by the industry in the pursuit of producing alternative products,achieving shelf life extension,and management and reducing food waste.In 2014,processed fish was among the most active new product categories.The lack of dissemination of validated laboratory results for the seafood industry is one of the major issues preventing the uptake of minimal and nonthermal processing for fresh fish.However,it has been reported that some bacteria become more resistant under stress(e.g.psychrotolerant lactobacilli).At the same time,the application of some processing methods(e.g.thermal processing)may affect significantly the nutritional and sensory profile of the target food product.The application of several“soft hurdles”may reduce the rate of fish deterioration and spoilage caused by microbial growth.The objective of this article is to review the preservative effect of alternative hurdles on fish quality and shelf life,focusing on recent,combined applications. 展开更多
关键词 hurdles FISH QUALITY SAFETY Kinetic modelling Shelf life
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Application of hurdle technology for the shelf life extension of European eel(Anguilla anguilla)fillets 被引量:2
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作者 Maria C.Giannakourou Natalia Stavropoulou +4 位作者 Theofania Tsironi Vladimiros Lougovois Vassiliki Kyrana Spyros J.Konteles Vassilia J.Sinanoglou 《Aquaculture and Fisheries》 CSCD 2023年第4期393-402,共10页
Fresh fish,and especially fatty species,are highly perishable due to oxidative deterioration of fish flesh and the elevated microbial load on fish surface.The implementation of a variety of“mild hurdles”may signific... Fresh fish,and especially fatty species,are highly perishable due to oxidative deterioration of fish flesh and the elevated microbial load on fish surface.The implementation of a variety of“mild hurdles”may significantly decrease the rates of fish chemical degradation and microbiological spoilage,by better retaining the initial quality,compared to more intense preservation techniques.The aim of this work is the comparative study of different,single or combined,treatments at 15℃on the quality and shelf life of chilled eel fillets.Fish fillets were treated using osmotic solutions consisting of glycerol(30%–40%–45%)and 5%NaCl with and without former antioxidant impregnation by using Rosemary Serum.In all cases,water activity decreased to approximately 0.90 after 420 min of osmotic treatment.Untreated and osmotically treated fish fillets were subsequently stored at 4℃and their stability under chill conditions was assessed based on microbial growth and oxidative deterioration.Microbial growth of treated samples was significantly delayed,especially due to the osmotic step(OS)and the derived water activity decrease.Lipid oxidation,a major cause of rejection for fatty fish such as eel,was greatly inhibited in treated fillets,owing to both‘hurdles’,aw lowering(OS)and antioxidant impregnation with rosemary serum(RS/OS),showing the synergistic effect of these successive procedures.Shelf life of treated eel fillets exhibited a more than 10-fold increase,as compared to the untreated samples,based on chemical composition and a 2 to 3-fold shelf life improvement,in terms of microbial growth. 展开更多
关键词 hurdle Eel fillets Osmotic treatment Rosemary extract Shelf life
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Modeling fire ignition probability and frequency using Hurdle models: a crossregional study in Southern Europe 被引量:1
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作者 Marina D’Este Antonio Ganga +6 位作者 Mario Elia Raffaella Lovreglio Vincenzo Giannico Giuseppina Spano Giuseppe Colangelo Raffaele Lafortezza Giovanni Sanesi 《Ecological Processes》 SCIE EI 2020年第1期634-647,共14页
Background:Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics.Numerous studies have investigated the wildfire occurrences and the influence of their drivers ... Background:Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics.Numerous studies have investigated the wildfire occurrences and the influence of their drivers in many countries of the Mediterranean Basin.However,in this regard,no studies have attempted to compare different Mediterranean regions,which may appear similar under many aspects.In response to this gap,climatic,topographic,anthropic,and landscape drivers were analyzed and compared to assess the patterns of fire ignition points in terms of fire occurrence and frequency in Catalonia(Spain),Sardinia,and Apulia(Italy).Therefore,the objectives of the study were to(1)assess fire ignition occurrence in terms of probability and frequency,(2)compare the main drivers affecting fire occurrence,and(3)produce fire probability and frequency maps for each region.Results:In pursuit of the above,the probability of fire ignition occurrence and frequency was mapped using Negative Binomial Hurdle models,while the models’performances were evaluated using several metrics(AUC,prediction accuracy,RMSE,and the Pearson correlation coefficient).The results showed an inverse correlation between distance from infrastructures(i.e.,urban roads and areas)and the occurrence of fires in all three study regions.This relationship became more significant when the frequency of fire ignition points was assessed.Moreover,a positive correlation was found between fire occurrence and landscape drivers according to region.The land cover classes more significantly affected were forest,agriculture,and grassland for Catalonia,Sardinia,and Apulia,respectively.Conclusions:Compared to the climatic,topographic,and landscape drivers,anthropic activity significantly influences fire ignition and frequency in all three regions.When the distance from urban roads and areas decreases,the probability of fire ignition occurrence and frequency increases.Consequently,it is essential to implement long-to medium-term intervention plans to reduce the proximity between potential ignition points and fuels.In this perspective,the present study provides an applicable decision-making tool to improve wildfire prevention strategies at the European level in an area like the Mediterranean Basin where a profuse number of wildfires take place. 展开更多
关键词 Driving factor Fire frequency Fire management Fire occurrence hurdle models Mediterranean Basin WILDFIRES
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Online Hurdle
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作者 TAN WEI 《Beijing Review》 2008年第33期34-34,共1页
Will a new regulation requiring online sellersto obtain business licenses impede the growth of consumer-to-consumer e-commerce?
关键词 Online hurdle
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One Hurdle Too Far
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作者 FRANCISCO LITTLE 《Beijing Review》 2008年第35期48-48,共1页
We sat around the office TV watching. All work had ground to a halt. The Bird’s Nest Olympic stadium was a full house and 90,000 pairs of eyes were
关键词 One hurdle Too Far
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Structural insights on anti-biofilm mechanism of heated slightly acidic electrolyzed water technology against multi-resistant Staphylococcus aureus biofilm on food contact surface 被引量:1
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作者 Pianpian Yan Ramachandran Chelliah +7 位作者 Kyoung Hee Jo Xiuqin Chen Akanksha Tyagi Hyeon Yeong Jo Fazle Elahi Nam Chan Woo Min Seung Wook Deog Hwan Oh 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1556-1566,共11页
Slightly acidic electrolyzed water(SAEW)has proven to be an efficient and novel sanitizer in food and agriculture field.This study assessed the efficacy of SAEW(30 mg/L)at 40℃on the inactivation of foodbome pathogens... Slightly acidic electrolyzed water(SAEW)has proven to be an efficient and novel sanitizer in food and agriculture field.This study assessed the efficacy of SAEW(30 mg/L)at 40℃on the inactivation of foodbome pathogens and detachment of multi-resistant Staphylococcus aureus(MRSA)biofilm.Furthermore.the underlying mechanism of MRS A biofilm under heated SAEW at 40℃treatment on metabolic profiles was investigated.The results showed that the heated SAEW at 40℃significantly effectively against foodbome pathogens of 1.96-7.56(lg(CFU/g))reduction in pork,chicken,spinach,and lettuce.The heated SAEW at 40℃treatment significantly reduced MRS A biofilm cells by 2.41(lg(CFU/cm^(2))).The synergistic effect of SAEW treatment showed intense anti-biofilm activity in decreasing cell density and impairing biofilm cell membranes.Global metabolic response of MRSA biofilms,treated by SAEW at 40℃,revealed the alterations of intracellular metabolites,including amino acids,organic acid,fatty acid,and lipid.Moreover,signaling pathways involved in amino acid metabolism,energy metabolism,nucleotide synthesis,carbohydrate metabolites,and lipid biosynthesis were functionally disrupted by the SAEW at 40℃treatment.As per our knowledge,this is the first research to uncover the potential mechanism of heated SAEW treatment against MRSA biofilm on food contact surface. 展开更多
关键词 Multi-resistant Staphylococcus aureus Metabolic profile SAEW BIOFILM hurdle technology Electrode material
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基于计数模型方法的林分枯损研究 被引量:14
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作者 张雄清 雷渊才 +2 位作者 雷相东 陈永富 冯淼 《林业科学》 EI CAS CSCD 北大核心 2012年第8期54-61,共8页
利用吉林省汪清林业局金沟岭林场落叶松林分连续观测数据,分别利用Poisson回归模型、负二项模型、零膨胀模型和Hurdle模型拟合林木枯损株数,并通过AIC值以及Vuong检验对这些模型进行详细分析比较。结果表明:Poisson回归模型不适用于模... 利用吉林省汪清林业局金沟岭林场落叶松林分连续观测数据,分别利用Poisson回归模型、负二项模型、零膨胀模型和Hurdle模型拟合林木枯损株数,并通过AIC值以及Vuong检验对这些模型进行详细分析比较。结果表明:Poisson回归模型不适用于模拟林木枯损株数,负二项回归模型相对于Poisson回归模型比较适用;但是对于零枯损过多的数据,这2类模型拟合效果较差。零膨胀模型和Hurdle模型对这类数据有很好的解决办法,其中,零膨胀负二项模型和Hurdle-NB模型拟合效果优于其他几种模型,且Hurdle-NB模型略好于零膨胀负二项模型。 展开更多
关键词 林分枯损 Poisson回归模型 负二项模型 零膨胀模型 hurdle模型
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黔南地区气象因子与森林火灾发生次数之间的关系 被引量:12
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作者 肖云丹 鞠洪波 +1 位作者 张雄清 纪平 《林业科学》 EI CAS CSCD 北大核心 2011年第10期128-133,共6页
对黔南区春季防火期森林火灾数据进行分析,分别引入Poisson回归模型、负二项模型、零膨胀负二项模型和Hurdle模型拟合该地区火险天气森林火灾发生数,并对这些模型进行逐步筛选。结果表明:Poisson回归模型不适用于处理过度离散的数据,负... 对黔南区春季防火期森林火灾数据进行分析,分别引入Poisson回归模型、负二项模型、零膨胀负二项模型和Hurdle模型拟合该地区火险天气森林火灾发生数,并对这些模型进行逐步筛选。结果表明:Poisson回归模型不适用于处理过度离散的数据,负二项回归模型相对于Poisson回归模型,比较适用于过离散数据;但是对于零个数过多的数据,这2类模型拟合效果较差,零膨胀负二项模型和Hurdle模型对这类数据有很好的解决办法。零膨胀负二项模型和Hurdle模型拟合效果优于其他2种模型,而且Hurdle模型好于零膨胀负二项模型。 展开更多
关键词 森林火灾 火险天气 Poisson回归模型 负二项模型 零膨胀负二项模型 hurdle模型
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